• Asia pacific journal of information systems
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• v.22 no.3
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• pp.53-74
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• 2012

A challenge in fostering virtual communities is the continuous supply of knowledge, namely members' willingness to contribute knowledge to their communities. Previous research argues that giving away knowledge eventually causes the possessors of that knowledge to lose their unique value to others, benefiting all except the contributor. Furthermore, communication within virtual communities involves a large number of participants with different social backgrounds and perspectives. The establishment of mutual understanding to comprehend conversations and foster knowledge contribution in virtual communities is inevitably more difficult than face-to-face communication in a small group. In spite of these arguments, evidence suggests that individuals in virtual communities do engage in social behaviors such as knowledge contribution. It is important to understand why individuals provide their valuable knowledge to other community members without a guarantee of returns. In virtual communities, knowledge is inherently rooted in individual members' experiences and expertise. This personal nature of knowledge requires social interactions between virtual community members for knowledge transfer. This study employs the social capital theory in order to account for interpersonal relationship factors and identity theory for individual and group factors that may affect knowledge contribution. First, social capital is the relationship capital which is embedded within the relationships among the participants in a network and available for use when it is needed. Social capital is a productive resource, facilitating individuals' actions for attainment. Nahapiet and Ghoshal (1997) identify three dimensions of social capital and explain theoretically how these dimensions affect the exchange of knowledge. Thus, social capital would be relevant to knowledge contribution in virtual communities. Second, existing research has addressed the importance of identity in facilitating knowledge contribution in a virtual context. Identity in virtual communities has been described as playing a vital role in the establishment of personal reputations and in the recognition of others. For instance, reputation systems that rate participants in terms of the quality of their contributions provide a readily available inventory of experts to knowledge seekers. Despite the growing interest in identities, however, there is little empirical research about how identities in the communities influence knowledge contribution. Therefore, the goal of this study is to better understand knowledge contribution by examining the roles of social capital and identity in virtual communities. Based on a theoretical framework of social capital and identity theory, we develop and test a theoretical model and evaluate our hypotheses. Specifically, we propose three variables such as cohesiveness, reciprocity, and commitment, referring to the social capital theory, as antecedents of knowledge contribution in virtual communities. We further posit that members with a strong identity (self-presentation and group identification) contribute more knowledge to virtual communities. We conducted a field study in order to validate our research model. We collected data from 192 members of virtual communities and used the PLS method to analyse the data. The tests of the measurement model confirm that our data set has appropriate discriminant and convergent validity. The results of testing the structural model show that cohesion, reciprocity, and self-presentation significantly influence knowledge contribution, while commitment and group identification do not significantly influence knowledge contribution. Our findings on cohesion and reciprocity are consistent with the previous literature. Contrary to our expectations, commitment did not significantly affect knowledge contribution in virtual communities. This result may be due to the fact that knowledge contribution was voluntary in the virtual communities in our sample. Another plausible explanation for this result may be the self-selection bias for the survey respondents, who are more likely to contribute their knowledge to virtual communities. The relationship between self-presentation and knowledge contribution was found to be significant in virtual communities, supporting the results of prior literature. Group identification did not significantly affect knowledge contribution in this study, inconsistent with the wealth of research that identifies group identification as an important factor for knowledge sharing. This conflicting result calls for future research that examines the role of group identification in knowledge contribution in virtual communities. This study makes a contribution to theory development in the area of knowledge management in general and virtual communities in particular. For practice, the results of this study identify the circumstances under which individual factors would be effective for motivating knowledge contribution to virtual communities.

• The korean journal of orthodontics
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• v.28 no.1 s.66
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• pp.75-83
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• 1998

This study was done to recognize the importance of errors in measurements of cephalometric radiograph and to find the anatomical structures those need special care to select as a reference points through the detection of the systematic errors and estimation of random errors. For this purose, 100 cephalometric radiographs were prepared by usual manner and 61 reference points, and 130 measurement variables were established. Measurement errors were detected and estimated by the comparison of the 25 randomly-selected samples for repeated measurements with the main sample. The following results were obtained : 1. In comparison of the repeated measurements, there were statistical significant differences in 24 variables which were 18.4% of 130 total variables. 2. The frequency of the difference in identification of the reference points between the repeated measurements was very high in the root apex of upper incisor(as), the most posterior wall of maxilla(tu), soft tissue nasion(n'), soft tissue frontal eminence(ft), and ad3 in airway. 3. After correction of reference points marking until the level of below 5% significance, the range of random errors were from 0.67 to 1.71 degree or mm. 4. The variable shown the largest random error was the interincisal angle(ILs-ILi). 5. Measurement errors were mainly caused by the lack of precision in anatomic definitions and obscure radiographic image. From the above results, the author could find the high possibility of errors in cephalometric measurements and from this point, we should include error analysis in all the studies concerning measurments. In is essential to have a concept of error analysis not only for the investigator but also for a reader of other articles.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.38 no.4
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• pp.295-304
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• 2020

The IPCC (Intergovernmental Panel on Climate Change) recommended the importance of preventive measures against extreme weather, and heat waves are one of the main themes for establishing preventive measures. In this study, we tried to analyze the heat vulnerable areas by considering not only spatial characteristics but also social characteristics. Energy consumption, popu lation density, normalized difference vegetation index, waterfront distance, solar radiation, and road distribution were examined as variables. Then, by selecting a suitable model, SLM (Spatial Lag Model), available variables were extracted. Then, based on the Fuzzy theory, the degree of vulnerability to heat waves was analyzed for each variable, and six variables were superimposed to finally derive the heat vulnerable area. The study site was selected as the Daegu area where the effects of the heat wave were high. In the case of vulnerable areas, it was confirmed that the existing urban areas are mainly distributed in Seogu, Namgu, and Dalseogu of Daegu, which are less affected by waterside and vegetation. It was confirmed that both spatial and social characteristics should be considered in policy support for reducing heat waves in Daegu.

• Journal of Intelligence and Information Systems
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• v.19 no.3
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• pp.73-91
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• 2013

Advertising market has been facing new challenges due to dramatic change in advertising channels and the advent of innovative media such as mobile devices. Recent research related to mobile devices is mainly focused on the fact that mobile devices could identify users'physical location in real-time, and this sheds light on how location-based technology is utilized to achieve competitive advantage in advertising market. With the introduction of smartphone, the functionality of smartphone has become much more diverse and context awareness is one of the areas that require further study. This work analyses the influence of context awareness value resulted from the transformation of advertising channel in mobile communication market, and our research result reflects recent trend in advertising market environment which is not considered in previous studies. Many constructs has intensively been studied in the context of advertising channel in traditional marketing environment, and entertainment, irritation and information are considered to be the most widely accepted variables that has positive relationship with advertising value. Also, in smartphone advertisement, four main dimensions of context awareness value are recognized: identification, activity, timing and location. In this study, we assume that these four constructs has positive relationship with context awareness value. Finally, we propose that advertising value and context awareness value positively influence smartphone advertising attitude. Partial Least Squares (PLS) structural model is used in our theoretical research model to test proposed hypotheses. A well designed survey is conducted for college students in Korea, and reliability, convergent validity and discriminant validity of constructs and measurement indicators are carefully evaluated and the results show that reliability and validity are confirmed according to predefined statistical criteria. Goodness-of-fit of our research model is also supported. In summary, the results collectively suggest good measurement properties for the proposed research model. The research outcomes are as follows. First, information has positive impact on advertising value while entertainment and irritation have no significant impact. Information, entertainment and irritation together account for 38.8% of advertising value. Second, along with the change in advertising market due to the advent of smartphone, activity, timing and location have positive impact on context awareness value while identification has no significant impact. In addition, identification, activity, location and time together account for 46.3% of context awareness value. Third, advertising value and context awareness value both positively influence smartphone advertising attitude, and these two constructs explain 31.7% of the variability of smartphone advertising attitude. The theoretical implication of our research is as follows. First, the influence of entertainment and irritation is reduced which are known to be crucial factors according to previous studies related to advertising value, while the influence of information is increased. It indicates that smartphone users are not likely interested in entertaining effect of smartphone advertisement, and are insensitive to the inconvenience due to smartphone advertisement. Second, in today' ubiquitous computing environment, it is effective to provide differentiated advertising service by utilizing smartphone users'context awareness values such as identification, activity, timing and location in order to achieve competitive business advantage in advertising market. For practical implications, enterprises should provide valuable and useful information that might attract smartphone users by adopting differentiation strategy as smartphone users are sensitive to the information provided via smartphone. Also enterprises not only provide useful information but also recognize and utilize smarphone users' unique characteristics and behaviors by increasing context awareness values. In summary, our result implies that smartphone advertisement should be optimized by considering the needed information of smartphone users in order to maximize advertisement effect.

• Journal of Korean Academy of Nursing
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• v.21 no.2
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• pp.150-167
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• 1991

The intent of this longitudinal descriptive correlational study is to investigate the change of the mother - infant interactions over the periods of one month, three months and six months of the infant's age. This study is also intended to explore the interrelationships among three major factors- the perception of pregnancy, the mother -infant inter-action and the maternal attitude. The samples participated are 36 pairs of mother and infant from two university hospitals in Seoul. A data collection was made, from October in 1988 to September in 1989, for each subject at five periods of time ; prenatal period (after 36 weeks in pregnancy), postpartum two or three days, one month, three months and six months of infant's age. The research tools used in this investigation are Mother - Infant Play Interaction Scale (MIPIS), Prenatal Self- Evaluation Questionnaire and Cohler's Maternal Attitude Scale. Some of the findings are as follows ; 1. There is a significant increase in the mother - infant interaction from one month to three months and six months of infant's age. The highest score of the mother - infant interaction during three periods is at the time of three months. 2. The primipara's mother -infant interaction is not affected by the demographic characteristics, such as age, education and vocation of mother, types of delivery, or sex of infant. 3. Among seven categories of the perception of pregnancy, the most positively perceived categories by primiparas are acceptance of pregnancy and identification of. a motherhood role : whereas the negative ones are preparation for labor, concern for well -being of self and baby, md fear of pain, helplessness and loss of control in order of negativity. 4. There is no significant relationship between the perception of pregnancy and the mother - infant interactions. 5. There is no significant change in the maternal attitude over the period of one month, three months, and six months of infant's age. 6. There is no significant relationship between the maternal attitude and the mother - infant interactions. 7, The significant relationships are (end between the perception of pregnancy and maternal attitude, especially in the categories of concern for well -being of self and baby, accetance of pregnancy, identification of a motherhood role, fear of pain, helplessness and loss of control, and relationship with husband. In conclusion, it is confirmed that primipara's mother-infant interactions change over time period, and that perception of pregnancy and the maternal attitude do not affect the mother-infant interactions despite a significat relationship between those two variables. The implications of this investigation include a suggestion that nurses need to teach and demonstrate to mothers how to care for and interact with their infants, with a view to improving the mother-infant interactions which can be obtained through the improvement of maternal sensitivity to their infants.

• Korean Journal of Veterinary Research
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• v.38 no.3
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• pp.544-552
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• 1998

A random study of 574 dairy farms in Gyeongnam area was designed to determine 1) management factors that may be associated with the occurrence of drug residues; 2) the dairy farmer's attitudes and knowledge about residues; 3) how these variables influence the occurrence of residues in dairy cattle. Management factors perceived as having the greatest influence on drug residues in milk were insufficient knowledge about withdrawal periods, errors due to hired help, insufficient identification and record of animals treated for mastitis, dry cow treatment for mastitis, and metritis treatment. Seventy-one percent of farms with residues problem used mixed own feeds compared with twenty-nine percent of farms with premedicated feeds. Factors significantly associated with the occurrence of residues were herd size, increased number of hired persons, increased frequency of use of mixed-own feeds, category of medicated feed, and producer's attitude toward the public health significance of residues. Our findings suggest that residue occurrence was mainly associated with errors due to hired help, insufficient knowledge about withdrawal periods, poor animal identification and records of treatment animals and use of medicated feeds. Any residue avodiance educational program needs to stress how to deal with these factors. This educational program should be directed to dairy farmers and employees, especially temporary employees. In addition, Dairy farmer's attitudes and knowledge about drug residues need to be improved. More evidence on the public healths significance of residues should be available to them. Because belife in importance of public healths concerns was related to successful residue avidance and because 81.3% of the dairy farmers with residue problem thought public healths concerns were less important than economic ones, it would be helpful to provide educational programs specifically directed to this issue. it may be useful to provide programs not only for the dairy farmers but also change of their concerns about on the public healths.

• Journal of the Korean Society of Radiology
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• v.12 no.1
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• pp.53-64
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• 2018

Using the AUDIT-K (Korean versions of alcohol use disorders identification test), it was able to select a large number of potential danger drinkers who routinely live. There were no statistically significant differences in age, religion, marital status, occupation, family history of alcohol drinking, age at onset of alcohol use, smoking, and BMI (body mass index). However, only education and drinking periods were statistically significant. These results are consistent with the previous study, which suggests that alcohol consumption is higher among men who are educated. The level of education also suggests that there is a need to look at the differences depending on what you learned and how. Alcohol consumption by education also shows different results. Also, drinking at a young age will lead to a longer drinking period, which is consistent with previous studies on the age at onset of drinking. In this study, drinking period was the most important factor of alcohol use disorder and it is considered that measures and education of national government system which can delay drinking age as much as possible is needed as a method to shorten drinking period.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.11
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• pp.5773-5775
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• 2012

Objective: To assess the diagnostic and prognostic value of AFP and des-gamma-carboxyprothrombin (DCP) in combination and alone for hepatocellular carcinoma. Materials and Methods: A case control study carried out in the Department of Biochemistry of Manipal College of Medical Sciences, Pokhara, Nepal between $1^{st}$ January 2010 and $31^{st}$ December 2011. The variables collected were age, gender, BMI, total proteins, albumin, AST, ALT, total bilirubin, DCP, AFP. Approval for the study was obtained from the institutional research ethical committee. Estimation of AFP was performed by ELISA reader for all cases. Analysis was done using descriptive statistics and confidence interval (CI). The data was analyzed using Excel 2003, R 2.8.0 Statistical Package for the Social Sciences (SPSS) for Windows Version 16.0 (SPSS Inc; Chicago, IL, USA) and the EPI Info 3.5.1 Windows Version. Results:The mean age of HCC cases was $53.6{\pm}14.93$ yrs. The percentage of females was less than males in both cases (23%) and controls (29%). The specificity of DCP reached 100% when its values was equal or greater than 150 (MAU/ml) for 0, 3, 6, 9, 12 months preceding the diagnosis of HCC. Similarly, the specificity for AFP was also nearly 100% when its value was equal or greater than 200 ng/ml 0, 3, 6, 9, 12 months earlier to the finding of HCC. The specificity of DCP (${\geq}40MAU/mL$) and AFP(${\geq}20$ ng/mL) in combination was 93%, 97%, 95%, 96%, 97% in respect to 0, 3, 6, 9, 12 months prior to the diagnosis of HCC. Conclusion: The combination of both DCP and AFP will improve the finding of initial HCC and the sensitivity of these markers was utmost at the time of HCC identification and noticeably lesser at former time points.

• Journal of Environmental Impact Assessment
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• v.25 no.6
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• pp.402-413
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• 2016

Marine oil spill accidents are occurring continuously due to the marine transportation of the oil. While building a preventive system for oil spill is uttermost necessary, we also need to have a systematic response system to handle the oil spills that inevitably occur. So far, studies have focused on the environmentally sensitive resources affected by oil spills. However, there is a need to conduct research to evaluate the damage to the socially and economically sensitive resources that make up the life of local residents. This study represents the process of building an analytical framework for the assessment of socioeconomic resources affected by marine oil spills. While it is important to provide a scheme for identification and indexation of socially and economically sensitive resources that is compatible with Korea's situations, using existing data for identifying socio-economically sensitive resources might also be meaningful. However, to allow accurate analysis for better evaluation, we need to select more applicable data among the various indicators. In this research, we have reviewed many existing case studies of sensitive resources, studies of the variables that have been used for indexing sensitive resources, and various factors considered in SIA (Social Impact Assessment). Based on the findings, we classify socio-economically sensitive resources into marine products acquisition, population, land usage, administrative area, and cultural heritage and tourist region.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.20 no.1
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• pp.65-73
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• 2007

In the inverse perturbation method, enormous computational resource was required to obtain reliable results, because all unspecified DOFs were considered as unknown variables. Thus, in the present study, a reduced system method is used to condense the unspecified DOFs by using the specified DOFs, and to improve the computational efficiency as well as the solution accuracy. In most of the conventional reduction methods, transformation errors occur in the transformation matrix between the unspecified DOFs and the specified DOFs. Thus it is hard to obtain reliable and accurate solution of inverse perturbation problems by reduction methods due to the error in the transformation matrix. This numerical trouble is resolved in the present study by adopting iterative improved reduced system(IIRS) as well as by updating the transformation matrix at every step. In this reduction method, system accuracy is related to the selection of the primary DOFs and Iteration time. And both are dependent to each other So, the two level condensation method (TLCS) is selected as Selection method of primary DOFs for increasing accuracy and reducing iteration time. Finally, numerical verification results of the present iterative inverse perturbation method (IIPM) are presented.