• Knowledge Management Research
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• v.24 no.2
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• pp.161-183
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• 2023

Social Q&A sites, where individuals freely ask and answer each other online, play an important role as a public knowledge repository. For their sustainable growth, social Q&A sites constantly need new askers and new answerers. However, previous studies have focused only on answerers, with little attention to new users or askers. This study examines the factors encouraging new users to continue using social Q&A sites based on motivational affordance theory and self-determination theory, and also investigates whether the factors differ depending on the types of users (i.e., new asker vs. new answerer). In addition, the moderating effect of prior experience with a member Q&A site was examined. Using logistic regression and XGBoost, we analyzed online activity data from 25,000 users in the Stack Exchange Network and found that design elements with motivational affordances had significant impacts on new users' continuance behavior. The experience of a member Q&A site negatively moderated the influence of the antecedents of continuance behavior. Interestingly, the influence of editing was not significant in the analysis of new users as a whole, but was significant in the separate analyses of askers (significantly negative) and answerers (significantly positive).

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.284-284
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• 2013

중 에너지 이온 산란 분석법(Medium Energy Ion Scattering Spectrometer, MEIS)은 50~500 keV로 이온을 가속 후 시료에 입사시켜 시료의 원자와 핵간 충돌로 산란되는 일차이온의 에너지를 측정하여 시료를 분석하는 기법으로, 원자층의 깊이 분해능으로 초박막의 표면 계면의 조성과 구조를 분석 할수 있는 유용한 미세 분석기술이다. 본 실험에서 에너지 70~100 keV의 He+ 이온을 사용하여 Pulse Width 1 ns의 Pulsed ion beam을 만들어 Start 신호로 사용하고 Delay-line-detector에 검출된 신호를 End 신호를 이용한 TOF-MEIS System을 개발하였다. 활용 가능한 분석시편으로 Ultra thin film 시편으로 1, 1.5, 2, 2.5, 3, 4 nm의 HfO2, 1.8, 4nm의 SiO2 시편을 분석 하였으며 Ultra Shallow Junction 시편으로 As Doped Si, Cs Doped Si 시편 및 Composition, Core/shell 구조의 Q-dot 시편으로 CdSe, CdSe/ZnS등 다양한 분석 실험을 진행 하였다. Composition, Core/shell 구조의 Q-dot 시편은 Diamond Like Carbon(DLC)의 Substrate에 Mono-layer로 형성하여 분석하였다.

• Korean Journal of Environment and Ecology
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• v.6 no.2
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• pp.113-126
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• 1993

To investigate the structure of the forest community of Huibang valley in Sobaeksan National Park, twenty five plots were set up and surveyed. According to the analysis of classification by DCA community divided 4 groups. The divided groups are Pinus densiflora community, Q. mongolica -P. densiflora community. Q. mongolica-Stewartia koreana-Carpinus laxiflora community, and Q. mongolica- Acer pseudosieboldianum community. In the analysis by ordination, CCA which points out the relationship among the environmental variables, species and plots indicated primary step of secondary succession. The successional trends of both techniques. seem to be from P. densiflora through Q. mongolica, Q. serrate to C. laxiflora(or S. koreana) in canopy layer below an altitude of 800 meters, and from Rhododendron mucronulaltum. Rh. schlippenbachli. Rhus trichocarpa through Styrax obassia. Lindera obtusiloba to Magnolia sieboldii, Corylus sieboldiana in subtree and shrub layer. The positive correlation between the stand ordination scores .and soil moisture and soil humus were calculated.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.2D
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• pp.191-203
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• 2008

According to a characteristic analysis of traffic accidents of industrial vehicles (RTSA 2007), the occurrence rate and lethality per 10,000 vehicles is 6.7 times higher and 5.3 times higher than that of non-industrial vehicles respectively. For the recent 10 years, in contrast to the 1.5% decrease of the annual rate of entire traffic accidents, the accident rate of industrial vehicles have been increasing 2.0% on the annual average. For the recent 10 years, the accidents of a freight truck and bus have been steadily falling off. But, in the case of a taxi, it has constantly been rising 5.6%. In these situations, the countermeasures to decrease the accident rate are suggested by grasping the inclination of taxi drivers through Q analysis which is character and psychology analysis method.

• Journal of the Korean GEO-environmental Society
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• v.13 no.1
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• pp.63-74
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• 2012

In Korea, grouting has been mostly designed and constructed by experiences without expert knowledge and theoretical study. So there are a lot of problems related to the quality and safty of grouting. Therefor, in this paper the quality management skills and method were discussed through out by using the auto-grouting method and field test of grouting for the construction. Through the limit water injection test of the soil, it make the optimum injection pressure and injection speed of grouting, and through the lugeon test of the rock, it make assess the permeability of before and after grouting. In order to prevent the hydraulic fracture of soil and break away from the grouts if it apply four kinds of mode of grouting stop criteria, injection effects can be improved. From the above characteristcs designers evalute the fitness values of injection pressure(p), injection speed(q) and grouting penetration time(t). So far, to record and manage pressure(p) and speed(q) of grouting autographic devices such as intergation flow-meter usually record data in a roll of paper. Intergration flow-meter can record grouting flow quantity exactly, but the recorded pressures differ from the any basis such as intitial, intermediate and final point. Therefore, it has been argued that is a need of reliable method to describe the connection between the pressure recorded by an intergration flow-meter and the special properties of the grouting target ground. auto-grouting method can describe the reliable connection between the grouting pressure and the special properties of the grouting target ground. So, in this paper by using auto-grouting method, it is expected that to secure basis of quality control techniques construction.

• Korean Journal of Environment and Ecology
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• v.5 no.1
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• pp.54-67
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• 1991

To investigate the structure of the plant community of Daewon valley forest in Mt. Chiri, eighty-nine plots were set up by the dumped sampling method. The classification by TWINSPAN and DCA ordination were applied to the study area in order to classify item into several groups based on woody plants and environmental variables. The classification had been successfully overlayed on an ordination of the same data using DCA. The plots can be classified into five groups by TWINSPAN and DCA. There are Pinus densiflora community. Quercus variabilis-Q. serrata community. Carpinus laxiflora community. Q. monogolica community and Cornus controversa-Q. mongolica community. The successional trends of tree species by both techniques seem to be from P. densiflora through Q. variabilis, Q. serrata to C. laxiflora on the low altitude and from Q. mongolica to C. controversa on the high altitude in the canopy layer. As a result of the analysis for the relationship between the stand scores of DCA and environmental variables. they had a tendancy to increase significantly from the P. densiflora community to C. laxiflora community that was soil moisture. the amount of soil humus and soil nutrients.

• Journal of the Korean Society for information Management
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• v.32 no.3
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• pp.397-412
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• 2015

The main goal of this study is to investigate how to route a question to some relevant users who have interest in the topic of the question based on users' topic interest. In order to assess users' topic interest, archived question-answer pairs in the community were used to identify latent topics in the chosen categories using LDA. Then, these topic models were used to identify users' topic interest. Furthermore, the topics of newly submitted questions were analyzed using the topic models in order to recommend relevant answerers to the question. This study introduces the process of topic modeling to investigate relevant users based on their topic interest.

• The Journal of the Korea Contents Association
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• v.18 no.8
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• pp.514-524
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• 2018

This study applied Q methodology to consumers who have experience using food trucks to understand subjective perception of food truck customers. The purpose of this study is to characterize the perceptual structure of food truck customers, to describe characteristics of the types and to suggest some implications. The results of the type analysis are as follows. The first type (N = 10): Food truck zone accessibility preferred type, the second type (N = 8): Complex entertainment experience type, the third type (N = 9) = 3): Fast food preference type. Future research on food trucks, restaurants, and tourism will be based on a variety of literature and empirical studies, and will be revised and supplemented with more detailed Q methodological questions and analytical techniques to analyze the various opinions of respondents in a more concrete and objective manner.

• Journal of the Korean Institute of Landscape Architecture
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• v.44 no.3
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• pp.65-78
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• 2016

LID(Low-Impact Development) has received a great deal of attention in the field of urban water management. The spread of LID technologies as a natural drainage system has led to a rise in consideration of the applicability of policy in Korea. In this respect, the purpose of this study is to analyze experts' perception about utilization, applicability of policy, and improvements of LID by using Q-methodology. The sample included 31 experts who were government employees, landscape architects, researchers, and professors related to LID. All participants completed a 28-statement Q-sort task. Data was analyzed by using QUANL computer software. As a result of this study, four distinct experts' perceptions about LID are identified: Policy Enforcement Oriented Type, Expert Understanding Oriented Type, Manual Oriented Type, and Effectiveness Oriented Type. This study suggested appropriate directions related to LID technologies, and it is helpful to apply the domestic type's LID and increase the efficiency of LID in Korea. However, this study has a limit in which the viewpoint of the researcher intervenes: a complementary searcher is needed to verify the validity by type in policy decision-making.

• The Korean Journal of Nuclear Medicine Technology
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• v.21 no.2
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• pp.31-36
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• 2017

Purpose Recently, the performance of PET/CT scanner has been improved and various techniques have been developed to increase the image quality such as Sensitivity and Resolution. The purpose of this study is to evaluate the usefulness of Q.Clear (a fully convergent iterative reconstruction) technique of GE Discovery IQ equipment to enhance the image quality. Materials and Methods All scans were acquired by Discovery IQ (GE Healthcare, MI, USA). In NEMA IEC Body Phantom test, Background to Hot-sphere (10 mm, 13 mm, 17 mm, 22 mm) ratio was 1:4 and scan time was 3 minutes. The images were reconstructed by VPHDs (VUE Point High-Definition + SharpIR) and Q.Clear to evaluate each Contrast. We injected 18F-FDG 187 M㏃ to PET/SPECT Performance Phantom. And then it was scanned for 4 minutes to evaluate Resolution and Uniformity. T-test statistical analysis was performed on SUVmax of small lesions less than 2 cm in 100 clinical patients regardless of disease type. Results In the NEMA IEC Body Phantom, the Contrast was $63.6{\pm}5.7%$ (VPHDs) and $75{\pm}4.8%$ (Q.Clear). In the PET/SPECT Performance Phantom, the Resolution was 9.2 mm (VPHDs) and 7.3 mm (Q.Clear). Uniformity of Q.Clear was 10.8% better than VPHDs. T-test statistic of the clinical patients showed a significant difference of p value of 0.021. Conclusion Both the phantom test and the clinical results showed that the quality of the image was improved in Q.Clear was applied. The SUVmax was highly measured in Q.Clear and the lesions were clearly distinguished visually. Therefore Q.Clear can be useful in various aspects such as dose-reduction, patients evaluation and image analysis.