• Title/Summary/Keyword: Depth of Interaction

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Formation of Clay Minerals by Water-Rock Interaction in the Fracture of Gneiss (편마암 열극에서의 물-암석 상호반응에 의한 점토광물 생성)

  • Jeong, Chan-Ho;Kim, Soo-Jin;Koh, Yong-Kwon
    • Journal of the Mineralogical Society of Korea
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    • v.7 no.1
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    • pp.49-61
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    • 1994
  • As the groundwater flows along the fractures of crystalline rocks, it will be in contact with the fracture walls mostly coated by secondary minerals which are quite different form those of host rocks. The presence of fracture-filling minerals in crystalline rocks is important on the view point of radioactive waste disposal because of their great surface reactivity. The Surichi drill hole of 200 m in depth in the Yugu area composed mainly of Precambrian gneiss was selected to study the formation process of clay minerals on the fracture wall of gneiss, and their relation with present groundwater. The water-rock interaction in fractures resulted in the formation of gibbsite and clay minerals. They are formed by two different processes : (1) Incongruent dissolution of feldspar by groundwater diffused from a fracture path into rock matrix produced smectite and illite in situ, (2) on the wall of fracture, gibbsite, kaolinite, smectite and illite are formed by precipitation of dissolved species in groundwater. They show the paragenetic sequence such as gibbsite${\leftrightarrow}$kaolinite${\leftrightarrow}$smectite or illite. The paragenetic sequence of fracture-filling minerals was controlled by increase of pH of groundwater, decrease of fracture permeability by precipitation of fillings, and immobility of alkali or alkaline earths in groundwater. The groundwater from the Surichi borehole is a $Na-HCO_{3}$ type with pH range of 8.6-9.2. The sodium and bicarbonate in groundwater would be supplied by the dissolution of albite and calcite, respectively. The saturation index of groundwater and surface water calculated by WATEQ4F indicates that gibbsite and kaolinite are under precipitation to equilibrium state, and that smectite and illite are under equilibrium to redissolution environment. The stability relation of clay minerals in the $Na_{2}O-Al_{2}O_{3}-SiO_{2}-H_{2}O$ system shows that kaolinite is stable for all waters.

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A Comparative Case Study on the Adaptation Process of Advanced Information Technology: A Grounded Theory Approach for the Appropriation Process (신기술 사용 과정에 관한 비교 사례 연구: 기술 전유 과정의 근거이론적 접근)

  • Choi, Hee-Jae;Lee, Zoon-Ky
    • Asia pacific journal of information systems
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    • v.19 no.3
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    • pp.99-124
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    • 2009
  • Many firms in Korea have adopted and used advanced information technology in an effort to boost efficiency. The process of adapting to the new technology, at the same time, can vary from one firm to another. As such, this research focuses on several relevant factors, especially the roles of social interaction as a key variable that influences the technology adaptation process and the outcomes. Thus far, how a firm goes through the adaptation process to the new technology has not been yet fully explored. Previous studies on changes undergone by a firm or an organization due to information technology have been pursued from various theoretical points of views, evolved from technological and institutional views to an integrated social technology views. The technology adaptation process has been understood to be something that evolves over time and has been regarded as cycles between misalignments and alignments, gradually approaching the stable aligned state. The adaptation process of the new technology was defined as "appropriation" process according to Poole and DeSanctis (1994). They suggested that this process is not automatically determined by the technology design itself. Rather, people actively select how technology structures should be used; accordingly, adoption practices vary. But concepts of the appropriation process in these studies are not accurate while suggested propositions are not clear enough to apply in practice. Furthermore, these studies do not substantially suggest which factors are changed during the appropriation process and what should be done to bring about effective outcomes. Therefore, research objectives of this study lie in finding causes for the difference in ways in which advanced information technology has been used and adopted among organizations. The study also aims to explore how a firm's interaction with social as well as technological factors affects differently in resulting organizational changes. Detail objectives of this study are as follows. First, this paper primarily focuses on the appropriation process of advanced information technology in the long run, and we look into reasons for the diverse types of the usage. Second, this study is to categorize each phases in the appropriation process and make clear what changes occur and how they are evolved during each phase. Third, this study is to suggest the guidelines to determine which strategies are needed in an individual, group and organizational level. For this, a substantially grounded theory that can be applied to organizational practice has been developed from a longitudinal comparative case study. For these objectives, the technology appropriation process was explored based on Structuration Theory by Giddens (1984), Orlikoski and Robey (1991) and Adaptive Structuration Theory by Poole and DeSanctis (1994), which are examples of social technology views on organizational change by technology. Data have been obtained from interviews, observations of medical treatment task, and questionnaires administered to group members who use the technology. Data coding was executed in three steps following the grounded theory approach. First of all, concepts and categories were developed from interviews and observation data in open coding. Next, in axial coding, we related categories to subcategorize along the lines of their properties and dimensions through the paradigm model. Finally, the grounded theory about the appropriation process was developed through the conditional/consequential matrix in selective coding. In this study eight hypotheses about the adaptation process have been clearly articulated. Also, we found that the appropriation process involves through three phases, namely, "direct appropriation," "cooperate with related structures," and "interpret and make judgments." The higher phases of appropriation move, the more users represent various types of instrumental use and attitude. Moreover, the previous structures like "knowledge and experience," "belief that other members know and accept the use of technology," "horizontal communication," and "embodiment of opinion collection process" are evolved to higher degrees in their dimensions of property. Furthermore, users continuously create new spirits and structures, while removing some of the previous ones at the same time. Thus, from longitudinal view, faithful and unfaithful appropriation methods appear recursively, but gradually faithful appropriation takes over the other. In other words, the concept of spirits and structures has been changed in the adaptation process over time for the purpose of alignment between the task and other structures. These findings call for a revised or extended model of structural adaptation in IS (Information Systems) literature now that the vague adaptation process in previous studies has been clarified through the in-depth qualitative study, identifying each phrase with accuracy. In addition, based on these results some guidelines can be set up to help determine which strategies are needed in an individual, group, and organizational level for the purpose of effective technology appropriation. In practice, managers can focus on the changes of spirits and elevation of the structural dimension to achieve effective technology use.

Hydrogeochemical Evolution Related to High Fluoride Concentrations in Deep Bedrock Groundwaters, Korea (국내 심부 암반지하수에서의 고농도 불소 산출과 관련된 수리지구화학 진화)

  • Kim Kyoung-Ho;Yun Seong-Taek;Chae Gi-Tak;Kim Seong-Yong;Kwon Jang-Soon;Koh Yong-Kwon
    • Economic and Environmental Geology
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    • v.39 no.1 s.176
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    • pp.27-38
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    • 2006
  • To understand the geologic and hydrogeochemical controls on the occurrence of high fluoride concentrations in bedrock groundwaters of South Korea, we examined a total of 367 hydrochemistry data obtained from deep groundwater wells (avg. depth=600 m) that were drilled fur exploitation of hot springs. The fluoride concentrations were generally very high (avg. 5.65mg/L) and exceeded the Drinking Water Standard (1.5 mg/L) in $72\%$ of the samples. A significant geologic control of fluoride concentrations was observed: the highest concentrations occur in the areas of granitoids and granitic gneiss, while the lowest concentrations in the areas of volcanic and sedimentary rocks. In relation to the hydrochemical facies, alkaline $Na-HCO_3$ type waters had remarkably higher F concentrations than circum-neutral to slightly alkaline $Ca-HCO_3$ type waters. The prolonged water-rock interaction occurring during the deep circulation of groundwater in the areas of granitoids and granitic gneiss is considered most important for the generation of high F concentrations. Under such condition, fluoride-rich groundwaters are likely formed through hydrogeochemical processes consisting of the removal of Ca from groundwater via calcite precipitation and/or cation exchange and the successive dissolution of plagioclase and F-bearing hydroxyl minerals (esp. biotite). Thus, groundwaters with high pH and very high Na/Ca ratio within granitoids and granitic gneiss are likely most vulnerable to the water supply problem related to enriched fluorine.

Research on the Effect of the Control Methods of Irrigation Water on the Growth and Yield of Paddy Rice. (한발기에 있어서 용수관리 방법이 수도생육과 그 수량에 미치는 영향에 관한 연구)

  • 김시원
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.13 no.1
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    • pp.2177-2190
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    • 1971
  • This experiment was made to determienthe effect of various soil moisture contents in simulated drought conditions on different stages of rice growth. The drought conditions were developed at such three rice-growing stages as transplanting, immediately after transplanting and young ear forming. Three different lengths of drought periods, which are ten days, twenty days and thirty days, were applied for each growing stage of rice. The rice variety used this experiment is Nong-rim 29. This experiment was conducted at the university farm of the Kon-Kuk University during the period of $1968{\sim}1970$. Three reprications for each of 12 treatments and split plot design were employed in this study. Bottomless wood square boxes, $1^m{\times}1^m{\times}1^m$, were burried in the test plot and box top was covered with poloyethylene sheets to avoid natural rainfall drops. Standard plots were irrigated continuously with a water depth of 40mm/day and those of drought treatments were irrigated continuously up to the beginning of the planned drought period, and they were irrigated again with a depth of 40mm/day up to the maturing stage of rice. Other methods for rice raising followed those methods developed by the Field Crops Experiment Station of the Office of Rural Development. During this experiments, climatic conditions in regard to rainfalls, sunshine hours, and temperatures were observed. According to this observation, those values measured deviate slightly from the annual means. However the growing condition of rice plants were normal. The pH value of irritation water is nearly neutral, and soils in the test plots are relatively fertile, being similar to ordinary paddy soils. Analysis of variances for number of stalks, plan-height, ear sprouting date, length of stalks, ear length, number of ears per plant, fertility, grain weitght, weight of plant, and yield were carried out. The variances for plant height, ear sprouting date, length of stalk ear length, and yield has statistical significance under drought treatments applied at three different growing stages. The variance showing the effect of lengths of drought period is highly significant for all the treatments studied except that of grain weight. The interaction between drought periods and drought treatments at different growing stages is significant for plant height, stalk length, ear length, number of ears, fertility and yield, these results indicated that droughts at different growing stages have influence on plant height, ear length, yield, and length of drought period also has strong influence on all factors studied except grain weight. The combination of drought treatments at different rice growing stages and lengths of drought periods has different effects on various agronomic characteristics, including yield. Plant height under drought treatment practiced at transplanting stage is the lowest, and drought treatment applied immediately after transplanting resulted in the least number of stalks. The effect of different lengths of drought periods on plant height and number of stalks depends signis ficantly on increasing days of drought. Ear sprouting date tends to be delayed for one or two days undedrought treatments at transplanting period and with increasing days of drought. Better yield is secured in drought treatment applied immediately after transplanting. Adverse effect war observed when drought treatment was applied at ear forming period. These effects may be attributed to the alternation of irrigation and drought causing vigorous root activity. In general, yield linearly decreases as the length of the drought period increases. The results obtained in this study demonstrate that, in order to mimimize damage due to drought, and, to save irrigation water, paddy fields, immediately after transplanting, may be not irrigated, since there is sufficient moisture in the soil, and that sufficient irrigation water should be applied again in the ear forming stage of rice plant.

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A Study on the Interactive Narrative - Focusing on the analysis of VR animation <Wolves in the Walls> (인터랙티브 내러티브에 관한 연구 - VR 애니메이션 <Wolves in the Walls>의 분석을 중심으로)

  • Zhuang Sheng
    • Trans-
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    • v.15
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    • pp.25-56
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    • 2023
  • VR is a dynamic image simulation technology with very high information density. Among them, spatial depth, temporality, and realism bring an unprecedented sense of immersion to the experience. However, due to its high information density, the information contained in it is very easy to be manipulated, creating an illusion of objectivity. Users need guidance to help them interpret the high density of dynamic image information. Just like setting up navigation interfaces and interactivity in games, interactivity in virtual reality is a way to interpret virtual content. At present, domestic research on VR content is mainly focused on technology exploration and visual aesthetic experience. However, there is still a lack of research on interactive storytelling design, which is an important part of VR content creation. In order to explore a better interactive storytelling model in virtual reality content, this paper analyzes the interactive storytelling features of the VR animated version of <Wolves in the walls> through the methods of literature review and case study. We find that the following rules can be followed when creating VR content: 1. the VR environment should fully utilize the advantages of free movement for users, and users should not be viewed as mere observers. The user's sense of presence should be fully considered when designing interaction modules. Break down the "fourth wall" to encourage audience interaction in the virtual reality environment, and make the hot media of VR "cool". 2.Provide developer-driven narrative in the early stages of the work so that users are not confused about the ambiguous world situation when they first enter a virtual environment with a high degree of freedom. 1.Unlike some games that guide users through text, you can guide them through a more natural interactive approach that adds natural dialog between the user and story characters (NPC). Also, since gaze guidance is an important part of story progression, you should set up spatial scene user gaze guidance elements within it. For example, you can provide eye-following cues, motion cues, language cues, and more. By analyzing the interactive storytelling features and innovations of the VR animation <Wolves in the walls>, I hope to summarize the main elements of interactive storytelling from its content. Based on this, I hope to explore how to better showcase interactive storytelling in virtual reality content and provide thoughts on future VR content creation.

A qualitative study on the process of maintaining the 'eating alone'(honbob) lifestyle (직장인의 '혼밥' 유지 과정에 대한 질적 연구)

  • Hye Jin Kwon;Younga Ju
    • Korean Journal of Culture and Social Issue
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    • v.24 no.4
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    • pp.657-689
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    • 2018
  • The purpose of this study is to develop a substantive theory on 'eating alone'(honbob)and the process of maintaining the lifestyle of eating alone for the need of a non-judgmental understanding on the new 'honbob' lifestyle. Data were collected through in-depth interviews with 10 male and female workers in Seoul and Gyeonggi-do, who voluntarily eat alone over 70% of their meals per week with the minimum duration of 5 years. Data analysis was performed using grounded theory proposed by Strauss & Corbin (1998) in the qualitative research method. As a result, a paradigm model on the process of maintaining 'honbob' was derived. Based on categorical analysis, the causal condition was 'not trying to tune' and the central phenomenon was 'following the desire to set efficiency as the top priority. Contextual conditions were 'the atmosphere of fierce competition', 'weakening of organizational culture', 'diffusion of individualistic culture'. The intervening conditions were 'personal trait and emotional experience', 'job characteristics of less organization culture'. The action/interaction strategies were 'accepting internal conflicts', 'acting in autonomy', 'finding relationship through media', and 'distancing from superficial relationship'. The consequences were 'enjoying time for self-exploration', 'valuing self-care', 'becoming a epicurean conventionalist', and 'becoming aware of the need for balance'. The core category has been shown as 'self-oriented in accordance to priority of efficiency and being able to appreciate the importance of social group'. The Such phenomenon passes through four different stages - first, the stage of weighing time efficiency while beginning hon-bob; second, the stage of conflict when one feels nervous and not free from others' view; third, the stage of adjustment to justify his/her 'hon-bob'; and the final stage of balance to perceive the importance of social group while going on 'honbob'. The study had the aim of increasing the understanding and acceptance of the new 'honbob' lifestyle through an in-depth exploration of office worker's 'honbob' experience and the process of maintaining 'honbob' so the society can better accept it and, further, to embrace co-existence of various cultures.

Effects of Hwangryunhaedok-Tang and Geongangbuja-Tang on the Change of Interleukin-6 and $TNF-{\alpha}$ Level Induced by LPS I.C.V. Injection in Mice (황연해독탕(黃連解毒湯)과 건강부자탕(乾薑附子湯)이 LPS유도에 의한 마우스 혈중 IL-6와 $TNF-{\alpha}$ 변화에 미치는 영향)

  • Park, Su-Hyun;Kwon, Yong-Uk;Lee, Tae-Hee
    • Herbal Formula Science
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    • v.15 no.1
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    • pp.185-197
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    • 2007
  • Objective : This study was conducted to investigate the effects of Hwangryunhaedok-Tang and Geongangbuja-Tang on the change of interleukin-6 (IL-6) and tumor necrosis $factor-{\alpha}$ ($TNF-{\alpha}$) level induced by LPS I.C.V. injection in mice. Method : We devided group into 6 mice and 6 mice were assingned to each group. In the normal group only saline was administered intragastrically, and in the control group LPS was injected intracerebroventricularly 1 hr after intragastric administration of saline. In the experiment groups Hwangryunhaedok-Tang(0.5g/kg, 1.0g/kg, 3.0g/kg) was administered intragastrically to mice 1 hr prior to LPS(100mg/mouse) I.C.V. injection.. Also Geongangbuja-Tang (0.5g/kg, 1.0g/kg, 3.0g/kg) was administered intragastrically to mice 1 hr prior to LPS(100mg/mouse) I.C.V. injection. To measure the plasma IL-6 and $TNF-{\alpha}$ level of mice, their blood samples were collected from retro-orbital plexus, immediately centrifuged at $4^{\circ}C$, and plasma was removed and stored frozen at $-83^{\circ}C$ for later determination of IL-6 and $TNF-{\alpha}$. The level of IL-6 and $TNF-{\alpha}$ production was measured by enzyme-linked immunosorbent assay in the plasma. Result : Regarding IL-6 level, The 0.5g/kg and the 1g/kg groups of Geongangbuja-Tang decreased IL-6 level. Especially the 3g/kg control group decreased IL-6 level significantly than the normal group(p<0.01). Regarding $TNF-{\alpha}$ level, the 3g/kg group of Geongangbuja-Tang decreased it significantly(p<0.05). Conclusion : These data revealed that Hwangryunhaedok-Tang might not have the anti imflammatory effect and Geongangbuja-Tang(3g/kg)might have the anti imflammatory effect by reducing the plasma IL-6 and $TNF-{\alpha}$ level in mice LPS Injection.EIM (Eighteen Incompatible Medicaments) is an important component in Oriental pharmacology and is directly related to clinical prescriptions. Medical practitioners argued that the definite cause and meaning of EIM was ambiguous and therefore debated the issue of clinical application of the EIM. This study conducted an in-depth literary research on the origin, meaning and contents of EIM with the purpose to contribute in its efforts to be used clinically. Even after thousands of years have past since establishment of Oriental medicine, EIM is still tabooed and was an obstacle that hindered ideologies. Modern herbal medicine texts claim that the use of EIM can reduce treatment effects and promote poisoning and side effects. However, since long ago, there has been medical practitioners who reject this as false. Recently, poisoning caused by EIM has been claimed to be from the toxicity of the drug itself, rather than the result of interaction between the drugs, and therefore they suggest that EIM is not a forbidden domain. In addition, EIM showed a difference in number depending on the era. However, this can be understood not as a definite number, but instead as a warning to be careful during combination of drugs for use as clinical medicine. Historically, there were very few cases in which EIM was used for clinical tests and thus, the clinical value is not, while others applied EIM directly to their bodies, which showed signs for the usefulness and potential of EIM for us. A more concrete and in-depth study must be made on EIM.

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Ad libitum Pasture Feeding in Late Pregnancy Does Not Improve the Performance of Twin-bearing Ewes and Their Lambs

  • Corner-Thomas, R.A.;Back, P.J.;Kenyon, P.R.;Hickson, R.E.;Ridler, A.L.;Stafford, K.J.;Morris, S.T.
    • Asian-Australasian Journal of Animal Sciences
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    • v.28 no.3
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    • pp.360-368
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    • 2015
  • The present study evaluated the effect of controlled ryegrass-white clover herbage availability from day 128 until day 142 of pregnancy in comparison to unrestricted availability, on the performance of twin-bearing ewes of varying body condition score (BCS; 2.0, 2.5, or 3.0) and their lambs. It was hypothesised that under conditions of controlled herbage availability, the performance of lambs born to ewes with a greater BCS would be greater than those born to ewes with a lower BCS. During the period that the nutritional regimens were imposed, the pre- and post-grazing herbage masses of the Control regimen ($1,070{\pm}69$ and $801{\pm}30$ kg dry matter [DM]/ha) were lower than the ad libitum regimen ($1,784{\pm}69$ and $1,333{\pm}33kg\;DM/ha$; p<0.05). The average herbage masses during lactation were $1,410{\pm}31kg\;DM/ha$. Nutritional regimen had no effect on ewe live weight, BCS and back fat depth or on lamb live weight, indices of colostrum uptake, maximal heat production, total litter weight weaned or survival to weaning (p>0.05). The difference in ewe BCSs and back fats observed among body condition groups was maintained throughout pregnancy (p<0.05). At weaning, ewes from the BCS2.0 group had lower BCS and live weight ($2.4{\pm}0.2$, $74.3{\pm}2.6kg$) than both the BCS2.5 ($2.6{\pm}0.2$, $78.6{\pm}2.4kg$) and BCS3.0 ewes ($2.7{\pm}0.2$, $79.0{\pm}2.6kg$; p<0.05), which did not differ (p>0.05). Ewe BCS group had no effect on lamb live weight at birth or weaning or on maximal heat production (p>0.05). Serum gamma glutamyl transferase concentrations of lambs born to BCS3.0 ewes were higher within 36 hours of birth than lambs born to BCS2.0 ewes and BCS2.5 ewes ($51.8{\pm}1.9$ vs $46.5{\pm}1.9$ and $45.6{\pm}1.9IU/mL$, respectively [p<0.05]). There was, however, no effect of ewe body condition on lamb plasma glucose concentration (p>0.05). Lamb survival was the only lamb parameter that showed an interaction between ewe nutritional regimen and ewe BCS whereby survival of lambs born to BCS2.5 and BCS3.0 ewes differed but only within the Control nutritional regimen ewes (p<0.05). These results indicate farmers can provide twin-bearing ewes with pre- and post-grazing ryegrass-white clover herbage covers of approximately 1,100 and 800 kg DM/ha in late pregnancy, provided that herbage covers are 1400 in lactation, without affecting lamb performance to weaning. The present results also indicate that under these grazing conditions, there is little difference in ewe performance within the BCS range of 2.0 to 3.0 and therefore they do not need to be managed separately.

An Exploration of the Influencing Factors and Development of Effective Models of Science Teacher Efficiency (과학 교사의 효능감 관련 요인 탐색을 통한 과학 교사 효능감 형성 모형 개발)

  • Choi, Sung-Youn;Kim, Sung-Won
    • Journal of The Korean Association For Science Education
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    • v.30 no.6
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    • pp.693-718
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    • 2010
  • This study investigated secondary school science teachers' experiences to explore the influencing factors in science teachers efficiency (STE). The participants, thirty three secondary school science teachers who have more than four years of teaching experience, were interviewed about describing each teacher's experience throughout one's years of teaching. The grounded theory introduced by Strauss and Corbin (1998) was used to analyze the data in this study. The results of paradigm analysis revealed that STE is influenced by 125 concepts, 38 sub-categories, and 16 categories. In a paradigm model, the central phenomenon was 'constructing STE', and the causal condition was 'want to be a teacher' as career choice motivation. The contextual conditions that have an affect on the central phenomenon were 'self awareness of the teacher' and 'social awareness of the teacher.' The mediate conditions, which facilitated or restrained the action/interaction strategies, were 'societal tendency', 'school climate', and 'personal context.' The action/interaction strategies to control the phenomenon were 'following the line,' 'identifying effective teaching strategies,' 'taking teacher education programs,' and 'contributing to school improvement.' The consequences were 'teacher's self awareness', 'challenge,' and 'stagnating in teaching.' The overall conclusion drawn from this research is that, the definition of STE is beliefs in science teachers' capabilities to set up objects in some school teaching context and, organize and execute the course of action required to attain these. Additionally, STE has three dimensions of teacher's behaviors: science instructional efficiency, efficiency in engaging students, and efficiency in managing school conditions. This study offers insight into the nature of STE and theoretical framework. These findings may give science teachers and teacher educators the practical knowledge necessary to build effective training programs and interventions that would help increase STE and facilitate effective teaching.

An Integrated VR Platform for 3D and Image based Models: A Step toward Interactivity with Photo Realism (상호작용 및 사실감을 위한 3D/IBR 기반의 통합 VR환경)

  • Yoon, Jayoung;Kim, Gerard Jounghyun
    • Journal of the Korea Computer Graphics Society
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    • v.6 no.4
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    • pp.1-7
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    • 2000
  • Traditionally, three dimension model s have been used for building virtual worlds, and a data structure called the "scene graph" is often employed to organize these 3D objects in the virtual space. On the other hand, image-based rendering has recently been suggested as a probable alternative VR platform for its photo-realism, however, due to limited interactivity. it has only been used for simple navigation systems. To combine the merits of these two approaches to object/scene representations, this paper proposes for a scene graph structure in which both 3D models and various image-based scenes/objects can be defined. traversed, and rendered together. In fact, as suggested by Shade et al. [1]. these different representations can be used as different LOD's for a given object. For in stance, an object might be rendered using a 3D model at close range, a billboard at an intermediate range. and as part of an environment map at far range. The ultimate objective of this mixed platform is to breath more interactivity into the image based rendered VE's by employing 3D models as well. There are several technical challenges in devising such a platform : designing scene graph nodes for various types of image based techniques, establishing criteria for LOD/representation selection. handling their transition s. implementing appropriate interaction schemes. and correctly rendering the overall scene. Currently, we have extended the scene graph structure of the Sense8's WorldToolKit. to accommodate new node types for environment maps. billboards, moving textures and sprites, "Tour-into-the-Picture" structure, and view interpolated objects. As for choosing the right LOD level, the usual viewing distance and image space criteria are used, however, the switching between the image and 3D model occurs at a distance from the user where the user starts to perceive the object's internal depth. Also. during interaction, regardless of the viewing distance. a 3D representation would be used, if it exists. Finally. we carried out experiments to verify the theoretical derivation of the switching rule and obtained positive results.

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