• The Journal of Korean Academy of Prosthodontics
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• v.41 no.6
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• pp.720-731
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• 2003

Statement of problem. The importance of fixture design and surface treatment. Purpose. The clinical success of dental in plants is affected by many factors such like as degree of osseointegration, the effective load dispersion for the prostheses, and a lot of attempts have been made to overcome the difficulties. In this study, efforts were made to find the possibility of clinical acceptance of the dental implants of newly designed surface and resorbable blast media surcace. Materials and methods. In this study, two groups of custom-made, screw-shaped implants were prepared. The first with the consisting of Branemark clone design and the other with the new design. These implants were divided into four groups according to the kinds of surface treatment. Four implants($AVANA^{(R)}$, Osstem, Busan, Korea)of each group were installed in twenty rabbits. Group A was consisted of Branemark done implant left as machined, Group B with Branemark clone implants with RBM(Resorbable blast media) surface, Group C with newly designed implants left as machined and Group D with newly designed implants with RBM surface. One of the twenty rabbits died from inflammation and the observation was made for six weeks. Specimens from four groups were observed using scanning electron microscopy with 40, 100, 1000 magnification power and microsurface structures were measured by white-light scanning interferometry for three dimensional surface roughness measurements(Accura $2000^{(R)}$, Intek-Plus, Korea.). Removal torque was measured in 17 rabbits using digital torque gauge(MGT 12R, Mark-10 corp., NY, U.S.A.) immediately after the sacrifice and two rabbits were used for the histologic preparation(EXAKT $310^{(R)}$, Heraeus Kulzer, wehrheim, Germany) of specimens and observed under light microscope. Resonance frequency measurement($Osstell^{(R)}$) was taken with the 19 rabbits at the beginning of the implant fixation and immediately after the sacrifice. Results. Following results were taken from the experiment. 1. The surface of the RBM implants as seen with SEM had rough and irregular pattern with reticular formation compared to that of fumed specimens showing different surface topographies. 2. The newly designed implant with RBM surface had high removal torque value among four groups with no statistical significance. The average removal torque was $49.95{\pm}6.70Ncm$ in Group A, $51.15{\pm}4.40Ncm$ in Group B, $50.78{\pm}9.37Ncm$ in Group C, $51.09{\pm}4.69Ncm$ in Group D. 3. The RFA values were $70.8{\pm}4.3Hz$ in Group A, $71.8{\pm}3.1Hz$ in Group B, $70.9{\pm}2.5Hz$, $72.7{\pm}2.5Hz$ in Group D. Higher values were noted in the groups which had surface treatment compared to the untreated groups with no statistical significance. 4. The results from the histomorphometric evaluation showed a mean percentage of bone-to-implant contact of $45{\pm}0.5%$ in Group A, $55{\pm}3%$ in Group B, $49.5{\pm}0.5%$ in Group C, and $55{\pm}3%$ in Group D. Quite amount of newly formed bone were observed at the surface RBM-treated implants in bone marrow space.

• Journal of Korean Classical Literature and Education
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• no.34
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• pp.41-74
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• 2017

This study aimed to investigate the narrative strategy and meaning of fantasy in classic novels and to derive the educational meaning from the fantasy of Sukhyangjeon. This study selected Sukhyangjeon because is considered a suitable literary text that embodies characteristics of fantasy inherent in classical novels through its successful portrayal of the fantasy genre and its high popularity during its time. Specifically, this study observed that the "notice of hardships" which repeatedly appears in the narration of Sukhyangjeon reinforces the fantasy of the novel as it serves as an advance notice of intervention from heaven. Therefore, this study investigated the relationship between the notice of hardships and fantasy by focusing on Sukhyang's life. The way in which the "notice of hardships" is a form of illusion realized it evident in the plot when heaven saves Sukhyang from her hardship even though it was heaven that had granted her those forms of hardship. Firstly, the "notice from heaven" constitutes the macro structure of Sukhyangjeon. Through it, readers realize the enormous power of heaven by seeing how Sukhyang's life has been realized in accordance with heaven's notice with that, it evokes a sense of respect to heaven. In addition, heaven saves Sukhyang from different forms of danger. It enhances a miraculous feeling, which the omnipotent power of heaven shows, against the innocent appearance of Sukhyang during her times of danger. Meanwhile, when heaven notifies Sukhyang and the surrounding people of their fate and subsequently realizes it through dreams, this act creates a mysterious atmosphere and improves the probability of the narrative. If so, the narrative meaning in reinforcing the fantasy of the novel by the use of "notice of hardships" could be revealed through Sukhyang's real life. First, the hardship in which Sukhyang has gone through is so realistic and detailed that the readers' feelings of empathy are evoked with the fear of the coming hardship, wailing together, and trying to resolve the inner anxiety through Sukhyang's happiness. Second, the heavenly beings who are touched by the good behaviors of Sukhyang save her from the dangers of death. This creates the belief in readers that heaven intervenes for the good people. Third, the active attitude that Sukhyang and Leesun show in the process of marriage helps them overcome their earthly hardship and preserve their relationship in heaven. This gives readers hope that they could go to a "higher life" after going through suffering. This fantasy of Sukhyangjeon helps readers overcome their anxieties of reality through fantasy and recognizes the importance of relationships to enhance a sense of unity and solidarity with others. Because of these elements, it is expected that the fantasy of Sukhyangjeon will have a meaningful value to modern readers.

• The Journal of Korean Philosophical History
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• no.28
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• pp.363-386
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• 2010

The purpose of this study is to examine the relationship between theory of Confucian moral cultivation and meditation. Recently our community is more interested in 'a disease of mind'. A view of world, life, values which derived from the distorted perception of 'a disease of mind' can not be treated by psychiatric methods. In this sense, 'a disease of mind' is different from psychiatric illness. In this reason, alternative therapies applying philosophy, literature, arts, and humanities are attracting attention. Meditation is also one of them. In general, Meditation has been developed in Buddhism, but its method is closely related with Confucianism. Buddhist meditation has a pessimistic view of the reality in human life, but that of Confucian philosophy has laid stress on the reality and ego in human life. At this point, the Confucian meditation could provide a clue of solution for us in treatment of a disease of human mind. So Confucian moral cultivation and meditation have a great significance for the treatment of this disease as a methodology. In general, mental healing or psychotherapy has been proceeded by way of dialogue. 'Talking Cure' was conceived to let clients themselves recognize their current situation and find out the problem: "what happened and what's wrong" in their minds. But it does not have a high possibility of successful cure for subjects who are in the state of frustration, confusion, and lost of value. And also it is very difficult to apply to special institutions such as correctional institutions and military soldier who are targeted by current application of Humanities therapy. On this sense, it seems to be valuable to apply Confucian cultivation of mind and meditation which have emphasized the importance of mind-control for this. This study tries to examine theoretically how to relate the Confucian cultivation of mind with meditation, and to suggest a model of Humanities therapy that could be applied by Toe-gye's 『The Method on Preservation of Human mind(活人心方)』. Although Confucian cultivation of mind could present a meaningful theory for curing the disease of mind, it is very difficult to put the theory into practice. It is because Confucian cultivation of mind in itself is a kind of instruction that you need to do in all of your life, and essentially it is difficult to expect a temporary effect by performance or practice. So a cure model of Confucian cultivation of mind will be suggested on this assumption and limitations. This model is attempted on the main purpose of Humanities therapy in accordance with the development of a Korean model.

• Journal of the Korean Graphic Arts Communication Society
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• v.30 no.3
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• pp.89-114
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• 2012

For as to world, the concern about the environment problem is enhanced than any other time in the past because of being 21 century. And the environment problem is highlighted as the world-wide issue. The time of the environment problem intimidates the alive of the mankind and presence of an earth over the time. It becomes the essentiality not being selection in the personal living or the economical viewpoint now to prepare for the climatic modification. As to the company management, the green growth period which it excludes the environment management considering an environment, cannot carry on the company the continued management comes. That is, in the change center of the management paradigm, there is the environment management. Nearly, the greenhouse gas which the publication industry is the environmental toxic material like all industries is generated. The greenhouse gas is ejected in the process of running the manufacturing process and print shop of the various kinds material used as the raw material of the book. Particularly, the tree felling for getting the material of the paper is known to reach the direct influence on the global warming. This study does according to an object it considers and organizes the environment parameter based on this kind of fact as to the publication industry. And it is determined as the reference which is used as the basic materials preparing the case that carbon exhaust right transaction(CAP and TRADE) drawing are enforced in all industries and is sustainable the management of the publication industry and reduces the environmental risk among the company many risk management elements and plans and enforces the publication related policy that there is a value. In the printing publication industry, this study tried to inquire into elements discharging the environmental pollutant or the greenhouse gas. Additionally, in the printed publication production process, it tried to inquire into the effort for an environment-friendly and necessity at the printing paper and the printers ink, regarded as the element discharging the greenhouse gas all kinds of the printing materials, operation of the print shop and all kinds of the machines and recycle process, and etc. These considerations make these industrial field employees aware of the significance about a conservation and environmental protection. They try to give a help in the subsequent study producing quantitatively each environmental parameter emission of green house gas. This makes the calculation of the relative $CO_2$ output reproached ultimately possible. Meanwhile, in a sense, many research protects and improving an environment in connection with the contents of research at the printing publication industrial field is in progress. There will be the voluntary human face that it has to protect an environment but this can not do by the outside factor according to all kinds of environment related law and regulation. Anyway, because of acting on company management as the factor of oppression, the increase of this environment-related correspondence cost could know that the research that the environment loading relates with a procurement and development, environment management system introduction, quality control standard, including, normalizing including a material, and etc. through the part of the effort to reduce the cost low was actively in progress. As to the green growth era, as follows, this paper prescribed the subject and alternative of the print publication industry. It is surrounded by the firstly new digital environment and the generation of the subject. And secondly the printing industry is caused by the point of time when the green growth leaves by the topic which is largest in the global industry and it increases. The printing publication industry has to prepare the bridgehead for the environment-friendly green growth as the alternative for this resolution with first. The support blown in each industry becomes the obligation not being selection. Prestek in which the print publishing was exposed to spend many energies and which is known as the practice of the sustainable print publishing insisted that it mentioned importance of the green printing through the white pages in 2008 and a company had to be the green growth comprised through the environment-friendly activity. The core management for the sustainable printing publication industry presented from Presstack white pages is compacted to 4 words that it is a remove, reduce, recover, and recycle. Second, positively the digital printing(POD) system should be utilized. In the worldwide print out market, the digital printing area stops at the level of 10% or so but the change over and growth of the market of an analog-to-digital will increase rapidly in the future. As to the CEO Jeff Hayes of the Infoland, the offset print referred to that it of the traditional method got old and infirm with the minor phase of the new printing application like the customer to be wanted publication and the print of the digital method led the market. In conclusion, print publishers have to grasp well the market flow in the situation where a digitalization cannot be generalized and a support cannot avoid. And it keeps pace with the flow of the digital age and the recognition about the effort for the development and environment problem have to be raised. Particularly, the active green strategy is employed for the active green strategy.

• Korean Journal of Heritage: History & Science
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• v.43 no.1
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• pp.56-85
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• 2010

UNESCO World Heritage Programme was introduced following the adoption of Convention Concerning the Protection of the World Cultural and Natural Heritage by the General Conference of UNESCO in 1972 in order to protect cultural and natural heritage with superb value for all mankind. Despite its short history of less than 40 years, it has been evaluated as one of the most successful of the cultural area projects of UNESCO with 890 world heritage registered worldwide. For systematic protection management of World Heritage, UNESCO, through systemization of registration, emphasis on the importance of preservation management plan, institutionalization of monitoring, and operation of World Heritage Fund, has utilized World Heritage Programme not just as a means of listing excellent cultural properties, but as a preservation planning tool, and accordingly, such policies have had a significant influence on the cultural heritage protection legislations of numerous nations. Korea has ratified World Heritage Convention in 1988, and with the registration of the Royal Tombs of the Joseon Dynasty in 2009, it has 9 World Heritage Sites. Twenty years have passed since Korea joined the World Heritage Programme. While World Heritage registration contributed to publicity of the uniqueness and excellence of Korean cultural properties and improvement of Korea's national culture status, it is now time to devise various legislative/systematic improvement means to reconsider the World Heritage registration strategy and establish a systematic preservation management system. While up until now, the Cultural Properties Protection Law has been amended to arrange for basic rules regarding registration and protection of World Heritage Sites, and some local governments have founded bodies exclusive for World Heritage Site management, a more fundamental and macroscopic plan for World Heritage policy improvement must be sought. Projects and programs in each area for reinforcement of World Heritage policy capacity such as: 1) Enactment of a special law for World Heritage Site preservation management; 2) enactment of ordinances for protection of World Heritage Sites per each local government; 3) reinforcement of policies and management functionality of Cultural Heritage Administration and local governments; 4) dramatic increase in the finances of World Heritage Site protection; 5) requirement to establish plan for World Heritage Site preservation protection; 6) increased support for utilization of World Heritage Sites; 7) substantiation and diversification of World Heritage registration; 8) sharing of information and experiences of World Heritage Sites management among local governments; 9) installation of World Heritage Sites integral archive; 10) revitalization of citizen cooperation and resident participation; 11) training specialized resources for World Heritage Sites protection; 12) revitalization of sustainable World Heritage Sites tourism, must be selected and promoted systematically. Regarding how World Heritage Programme should be domestically accepted and developed, the methods for systemization, scientific approach, and specialization of World Heritage policies were suggested per type. In the future, in-depth and specialized researches and studies should follow.

• Journal of Distribution Research
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• v.17 no.3
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• pp.59-92
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• 2012

With accumulated research evidence, there is little doubt that leadership behavior is related to a wide variety of positive individual and organizational outcomes. Indeed, leadership behavior has been empirically linked to increased employee satisfaction, organizational commitment, extra effort, turnover intention, organizational citizenship behavior, and overall employee performance. Although leadership behavior has been linked to a number of positive organizational outcomes, research regarding the antecedents of such behavior is limited. Especially there is little research dealing with the antecedents of inter-organizational leadership behavior. This study interests in inter-organizational ethical leadership among marketing channel members. In both the mass media and the academic association, there has been a surge in interest in the ethical and unethical behavior of leaders. Although the corporate scandals in recent years may explain much of the mass media and popular focus, academics' interest has been limited by evidence that ethical leadership behavior is associated with both positive and negative inter-organizational processes and performances. This study tried to contribute to this body of knowledge by examining antecedents of ethical leadership. Ethical leadership is defined "the demonstration of normatively appropriate conduct through personal actions and interpersonal relationships, and the promotion of such conduct to followers through two-way communication, reinforcement, and decision-making." Ethical leaders not only inform individuals of the behefits of ethical behavior and the cost of inappropriate behavior, such leaders also set clear standards and use rewards and fair and balanced punishment to hold followers accountable for their ethical conduct. Despite the assume importance and prominence of ethical leadership among organizations, there are still many questions relating to its antecedents and consequences. One is whether the likelihood of an leading organization being perceived as an ethical leader among other following organizations in marketing channels can be predicted using its characteristics and inter-organizational relationship maintenance skills. Identifying trait and skill antecedents will aid in the development of strategies for selecting and developing ethical leaders and determining the best means to reinforce ethical behaviors. The purpose of this study is to investigate the effects of three categorized variables on ethical leadership of channel leader. To be concrete, this study develops a model of the antecedents of three conceptually distinct forms of channel leader characteristics, such as organizational traits, inter-organizational relationship maintenance strategies, and supplier management strategies, and tests the hypothesized differential effects on ethical leadership of marketing channel leaders. The reason why this study deals with discount store channel is that there is very strong inter-dependence between a discount store and its suppliers. Their strong inter-dependence makes their relationship as the relationship between a leader and suppliers and creates an atmosphere that leadership occur without difficulty. The research model is as follows. For the purpose of empirical testing, 295 respondents of suppliers of discount store channel in Korea were surveyed. The procedures included scale reliability, and discriminant and convergent validity were used to validate measures. Also, the reliability measurements traditionally employed, such as the Cronbach's alpha, were used. All the reliabilities were greater than .70. This study conducted confirmatory factor analyses to assess the validity of our measurements. All items loaded significantly on their respective constructs(with the lowest t-value being 15.2), providing support for convergent validity. We then examined composite reliability and average variance extracted(AVE). The composite reliability of each construct was greater than .70. The AVE of each construct was greater than .50. This study tested research model using Partial Least Square(PLS). The estimation of the structural equation model revealed an acceptable fit of the model to the data($r^2$=.851). Thus, This study concluded that the model fit was considered acceptable. The results of PLS are as follows. The results indicated that conscientiousness, openness, conflict management, social networks, training, fair reward had positive effects on ethical leadership of channel leaders. On the other hand, emotional insecure had negative effect and agreeableness, assurance, and inter-organizational communication had no significant effect on supply chain leadership.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.10
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• pp.6234-6241
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• 2014

The purpose of this study was to examine the status of medical staff stress and accommodating manners on the death of patients in a hospital setting for serving the basic information to develop a death education program of medical personnel from April 1 to April 30, 2014. A survey was performed on 353 medical personnel at K university hospital, located in Daejeon metropolitan city. Frequency analysis, chi-square test, and independent t-test were used to analyze the data. The results showed that 'to understand the value of the time and preparedness of a meaningful future' were the most important perspectives on the contents of death education (p<0.05), 'in order to change perceptions and attitudes toward death positively' was the most important reason why they required death education'(p<0.05), 'case-based teaching and problem-based learning' was the most effective way of death education (p<0.05), 'negative or hostile response of a patient's guardian to medical personnel' was the largest stress that medical personnel confront upon witnessing a death'(p<0.05). An understanding of the death of patients by medical personnel and an awareness of the need for death education will help improve the understanding of the patient, their guardian, and medical personnel themselves. The main findings will contribute to the development of a specific death education program on the medical personnel in a hospital setting.

• Journal of dental hygiene science
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• v.8 no.3
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• pp.123-129
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• 2008

The purpose of this study was to investigate the actual conditions of the subjective oral malodor perception of the survey subjects. Through the subjective questionnaire method over about 3 months from June to August in 2007, the data was collected targeting 275 adults. Statistical methods used were Chi-square test, Fisher's exact test and One-way ANOVA. And, the following results were obtained. 1. When having seen the ratio of those who were conscious of oral malodor, the adults, who responded with saying of feeling oral malodor at present and at ordinary times, accounted for 68.4% and 79.3%, respectively. And, the adults, who responded with saying of not feeling, were indicated to be 31.6%(at present) and 20.7%(at ordinary times), respectively. 2. Almost 83.5% of total people answered that they had most severe oral malodor at the time of awakening and 51.9% of subjects answered tongue contributed to the their oral malodor. 3. About the type of oral malodor, although 37.2% of the group thought the type of oral malodor was a food smell and fetid smell was second general burning smell occurred the time of hunger(22.5%). 4. In the answers of hoping for treatment of oral malodor, 66.9% of the people showed positive response to dental treatment for controlling their oral malodor. Especially 7.3% of subjects showed very big desire for treatment. 5. In the level of oral malodor that is felt now according to the time of a meal, the case of within 1 hour after having a meal was responded to be not felt the oral malodor with 44.7%. And, there was response with saying of not feeling oral malodor in 37.6% as for 1-2 hours, 16.3% as for 2-3 hours, 14.8% as for 3-4 hours, and 23.7% as for more than 4 hours. Thus, the level of oral malodor according to the time of a meal showed the statistically significant difference(p<0.01). Through the results of this study, it could be known about whether or not being conscious of oral malodor in general people, the main cause and region for oral malodor, the importance and practicing method of tongue brush through literature. Accordingly, there is necessity of further researching and comparing whether or not being conscious of oral malodor by diversely surveying relevancy with factors of causing oral malodor based on the objective oral malodor measurement value. The future diverse researches are thought to be necessarily performed in order to prevent or reduce oral malodor.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.30 no.2
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• pp.64-71
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• 2012

This is a basic study for recovering original form of Nongsanbyeoleop(農山別業) in Gangjin, Jeonnam, created in the latter part of Joseon period and the estimation of originla form at the time of creation was conducted by analyzing related literature and inspecting the actual site. "Joseokruki(朝夕樓記)" of Dasan Jung, Yak Yong could estimate spatial structure and using form of Nongsanbyeoleop and the arrangement of spatial structure in literature could be confirm by on-the-site inspection. The results of this study are as follows. The first, Nongsanbyeoleop managed spatial factors applying natural topography. For the spatial characteristics of Nongsanbyeoleop, the location of ancestral ritual space including deceased father's tomb and tomb house far from the main levee of Yun, Kwang Taek, a father of Yun, Seo Yu by 1.9km and housekeeping could be confirmed. The second, spatial estimation by "Joseokruki" could be possible. "Joseokruki" describes Joseokru.Youngmojae.Hanokkwan.Cheokyunjung.Sangam as construction factors, Wundang.Kookdan.Nokwunoh. as plant factors, Sookyunggan.Keumkoji.Nokeumjung.Uijanghae as hydroponic factors and Pyoeunkok.Aengjakang as natural topography factors. However, most of them were disappeared and at present, only Youngmojae, Keumgoji, Kukdan and Wundang show the past trace. The third is for the changed space of Nongsanbyeoleop and its reason. The surrounding space of Nongsanbyeoleop was planated by land arrangement in 1960s and it played a role of topographical damage because it's recognized as the plane factor including Nongsanbyeoleop's surrounding landscape rather than dotted factor. The forth, the actual measurement of Nongsanbyeoleop and digitalization of manual map of numerical value are judged to be sufficient to apply as the basic material for recovering garden in the future. Because of the diatahce changing method applied at that time, the garden recovery of Nongsanbyeoleop intended to be concreted and 3D model established by digitalized basic materials is considered to apply for multilateral studying. Thus, Nongsanbyeoleop which is byeolseo including the tomb of deceased father based on the conceptual hyo thought shows clear differences from the organized factors of Byolseowonrim of precedent studies and the importance of Byolseowonrim is sufficient. But, the constructional factors which cannot know disappeared spatial factors and accurate location became the limitation of this study. In the future, clear verification of original form must be progressed by excavation which can confirm the location of construction factors.

• 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.