• Journal of Dental Rehabilitation and Applied Science
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• v.16 no.3
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• pp.171-185
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• 2000

The treatment objectives of the complete oral rehabilitation are : (1) comfortably functioning temporomandibular joints and stomatognathic musculature, (2) adherence to the basic principle of occlusion advocated by Schuyler, (3) anterior guidance that is in harmony with the envelope of function, (4) restorations that will not violate the patient's neutral zone. There may be many roads to achieving these objectives, but they all convey varing degrees of stress and strain on the dentist and patient. There are no "easy" cases of oral rehabilitation. Time must be taken to think, time must be taken to plan, and time must be taken to perform, since time is the critical element in both success and failure. Moreover, a systematized and integrated approach will lead to a prognosis that is favorable and predictable. This approach facilitates development of optimum oral function, comfort, and esthetics, resulting in a satisfied patient. Such a systematized approach consists of four logical phase : (1) patient evaluation, (2) comprehensive analysis and treatment planning, (3) integrated and systematic reconstruction, and (4) postoperative maintenance. Firstly, we must evaluate the mandibular position. The results of a repetitive, unstrained, nondeflective, nonmanipulated mandibular closure into complete maxillomandibular intercuspation is not so much a "centric" occlusion as it is a stable occlusion. Accordingly, we ought to concern ourselves less with mandibular centricity and more with mandibular stability, which actually is the relationship we are trying to establish. The key to this stability is intercuspal precision. Once neuromuscular passivity has been achieved during an appropriate period of occlusal adjustment and provisionalization, subsequent intercuspal precision becomes the controlling factors in maintaining a stable mandibular position. Secondly, we must evaluate the planned vertical dimension of occlusion in relationship to what may now be an altered(generally diminished), and avoid the hazard of using such an abnormal position to indicate ultimate occlusal contacting points. There are no hard and fast rules to follow, no formulas, and no precise ratios between the vertical dimension of occlusion. Like centric relation, it is an area, not a point.

• The Journal of Korean Academy of Prosthodontics
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• v.43 no.1
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• pp.61-77
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• 2005

Statement of problem. The implant prosthesis has been utilized in various clinical cases thanks to its increase in scientific effective application. The relevant implant therapy should have the high success rate in osseointegration, and the implant prosthesis should last for a long period of time without failure. Resorption of the peri-implant alveolar bone is the most frequent and serious problem in implant prosthesis. Excessive concentration of stress from the occlusal force and biopressure around the implant has been known to be the main cause of the bone destruction. Therefore, to decide the location and angulation of the implant is one of the major considering factors for the stress around the implant fixture to be dispersed in the limit of bio-capacity of load support for the successful and long-lasting clinical result. Yet, the detailed mechanism of this phenomenon is not well understood. To some extent, this is related to the paucity of basic science research. Purpose. The purpose of this study is to perform the stress analysis of the implant prosthesis in the partially edentulous mandible according to the different nature locations and angulations using three dimensional finite element method. Material and methods, Three 3.75mm standard implants were placed in the area of first and second bicuspids, and first molar in the mandible Thereafter, implant prostheses were fabricated using UCLA abutments. Five experimental groups were designed as follows : 1) straight placement of three implants, 2) 5$^{\circ}$ buccal and lingual angulation of straightly aligned three implants, 3) 10$^{\circ}$ buccal and lingual angulation of straightly aligned three implants. 4) lingual offset placement of three implants, and 5) buccal offset placement of three implants. Average occlusal force with a variation of perpendicular and 30$^{\circ}$ angulation was applied on the buccal cusp of each implant prosthesis, followed by the measurement of alteration and amount of stress on each configurational implant part and peri-implant bio-structures. The results of this study are extracted from the comparison between the distribution of Von mises stress and the maximum Von mises stress using three dimensional finite element stress analysis for each experimental group. Conclusion. The conclusions were as follows : 1. Providing angulations of the fixture did not help in stress dispersion in the restoration of partially edentulous mandible. 2. It is beneficial to place the fixture in a straight vertical direction, since bio-pressure in the peri-implant bone increases when the fixture is implanted in an angle. 3. It is important to select an appropriate prosthodontic material that prevents fractures, since the bio-pressure is concentrated on the prosthodontic structures when the fixture is implanted in an angle. 4. Offset placement of the fixtures is effective in stress dispersion in the restoration of partially edentulous mandible.

• Journal of Digital Convergence
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• v.10 no.9
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• pp.239-251
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• 2012

This study aims to seek the policies and the plans for the successful small business start-up through an exploratory study about the factors affecting the success rate of small business start-up. To measure the performance of the start-up business(sales revenue, net profit, and outcome expectancy), the characteristics of founders (experience, psychological characteristics) and the preparation of small business start-up were measured as independent variables and the self-efficacy was measured as a parameter. 427 small business owners were targeted and structured self-administered questionnaires were collected from them. For the data process, a multiple regression analysis by SPSS 18.0 was conducted. The findings demonstrated the experience in the same business, the need for achievement, the risk-taking propensity, the preparation period for business start-up had a significant effect on self-efficacy, and experience of failure and the ratio of net worth had a significant effect on sales revenue and net profit, and the locus of control had a significant effect on outcome expectancy through the self-efficacy, a parameter. It was also noted the self-efficacy of small business owners and the business performance varied depending on the characteristics of them and the preparation process of the business start-up. Based on the those findings, the theoretical and practical implications were discussed and the suggestions about the limits of the study, future policies and studies were made.

• Journal of Periodontal and Implant Science
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• v.31 no.3
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• pp.581-595
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• 2001

In performing implant procedures in the anterior portion of the maxilla, many difficulties exist because of anatomical reasons, such as the proximity of the nasal floor, lateral extension of the incisive canal, and labial concavity. On the other hand, in the posterior region of the maxilla, there is often insufficient recipient bone between the maxillary sinus and alveolar ridge due to alveolar ridge resorption and pneumatization of the maxillary sinus. In order to perform implants in such regions, ridge augmentation procedures such as onlay bone graft, guided bone regeneration, and maxillary sinus grafting are performed. In studies of Caucasians, use of autograft from mandibular symphysis has been reported to be highly successful in maxillary sinus grafting. However, in a clinical study of Koreans, autograft of mandibular symphysis has been reported to have significantly low success rate. It has been hypothesized that this is because of insufficient cancellous bone due to thick cortical bone. In order to test this hypothesis, bone quality and morphology of Koreans can be compared with those of Caucasians. In this study, the bone density and morphology of the cortical bone and cancellous bone in the mandibular symphysis of 35 Korean cadavers were evaluated. The following results were obtained: 1. In terms of bone density, type I, type II, and type III consisted of 1.4%(3/213), 72.3%(154/213), and 26.3%(56/213) of the cross-sectioned specimens, respectively. In general, the bone density tended to change from type II to type III, as cross-sectioned specimens were evaluated from the midline to the canine. Type IV wasn't observed in this study. 2. The distance between the root apex and the lower border of the cancellous bone was 18.34mm-20.59mm. Considering that the bone has to be cut 5mm below the root apex during the procedure, autografts with about 15mm of vertical thickness can be obtained. 3. The thickness of cortical bone on the labial side increased from the root apex to the lower border of the mandible. The average values ranged from 1.43mm to 2.36mm. 4. The labio-lingual thickness of cancellous bone ranged from 3.43mm to 6.51mm. The thickness tended to increase from the apex to the lower border of the mandible and decrease around the lower border of cancellous bone. From the above results, the anatomic factors of the mandibular symphysis (bone density, thickness, quantity and length of the cortical bone and cancellous bone) didn't show any difference from Caucasians, and it cannot be viewed as the cause of failure in autografts in the maxillary sinus for implants.

• Journal of Korea Entertainment Industry Association
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• v.15 no.4
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• pp.359-367
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• 2021

This study tried to examine the factors that affect the entrepreneurial intentions in the field of culture and tourism industry. Through this, it was attempted to present strategic implications for start-up plans to prospective entrepreneurs in the cultural tourism industry. As a result of the study, the following implications were drawn. First, prospective entrepreneurs in the field of culture and tourism industry need to analyze the start-up items they want to start and systematically design a start-up plan based on market research. Also, by analyzing various start-up cases, it is necessary to secure various prior experiences of failure and success. Second, prospective entrepreneurs in the field of culture and tourism industry will need to increase their interest in starting a business by completing various entrepreneurship education conducted by more diverse institutions and schools than now, and they will have to increase the sense of achievement and willpower that can appear in education. In addition, by making efforts to create human relationships through various entrepreneurship education, efforts should be made to show the utilization of human networks and information sharing when starting a business. Lastly, prospective entrepreneurs in the field of culture and tourism industry should visit startup-related institutions and receive education and advice from experts in order to acquire various information. In addition, efforts should be made to provide more diverse start-up support by obtaining information on start-ups implemented by the state.

• Journal of the Korea Society of Computer and Information
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• v.18 no.9
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• pp.165-175
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• 2013

Though the number of food franchises has been increased these days, there has not been less success for food franchise than failure. One of the several failures is the distrust between franchisor and franchisee factors because the franchisee thought its franchisor does not make its accounts and operations transparent. In order to resolve it, the large business food franchise has used the ERP system, however, small business franchise has run a very simple information system, which is linked to POS system and consists of simple functions to insert or inquire the result of data on sales and order etc to identify the status of both franchisor and franchisee because of financial difficulties and manpower shortage. Thus, small business franchise needs the cost management between them with low cost for efficient business administration. In this study, we suggest the data reference model (DRM) which covers the cost management system and is able to be linked to any POS system. The DRM is a framework whose primary purpose is to enable information linking and reuse across the any POS-based information systems via the classification, structure, model, exchange and management of data.

• The Journal of Korean Academy of Prosthodontics
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• v.40 no.5
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• pp.507-524
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• 2002

Load transfer of implant overdenture varies depending on anchorage systems that are the design of the superstructure and substructure and the choice of attachment. Overload by using improper anchorage system not only will cause fracture of the framework or screw but also may cause failure of osseointegration. Choosing anchorage system in making prosthesis, therefore, can be considered to be one of the most important factors that affect long-term success of implant treatment. In this study, in order to determine the effect of anchorage systems on load transfer in mandibular implant overdenture in which 4 implants were placed in the interforaminal region, patterns of stress distribution in implant supporting bone in case of unilateral vertical loading on mandibular left first molar were compared each other according to various types of anchorage system using three-dimensional photoelastic stress analysis. The five photoelastic overdenture models utilizing Hader bar without cantilever using clips(type 1), cantilevered Hader bar using clips(type 2), cantilevered Hader bar with milled surface using clips(type 3), cantilevered milled-bar using swivel-latchs and frictional pins(type 4), and Hader bar using clip and ERA attachments(type 5), and one cantilevered fixed-detachable prosthesis(type 6) model as control were fabricated. The following conclusions were drawn within the limitations of this study, 1. In all experimental models. the highest stress was concentrated on the most distal implant supporting bone on loaded side. 2. Maximum fringe orders on ipsilateral distal implant supporting bone in a ascending order is as follows: type 5, type 1, type 4, type 2 and type 3, and type 6. 3. Regardless of anchorage systems. more or less stresses were generated on the residual ridge under distal extension base of all overdenture models. To summarize the above mentioned results, in case of the patients with unfavorable biomechanical conditions such as not sufficient number of supporting implants, short length of the implant and unfavorable antero-posterior spread. selecting resilient type attachment or minimizing distal cantilever bar is considered to be appropriate methods to prevent overloading on implants by reducing cantilever effect and gaining more support from the distal residual ridge.

• The Journal of the Korea Contents Association
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• v.15 no.12
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• pp.541-549
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• 2015

Research about U.S. and European countries demonstrated that startups and young firms account for nearly all net job creation. If we want to bring down unemployment and to increase economic growth rate, we need to create new companies and to make them to grow. Credit availability is one of the most important factors for entrepreneurs as they attempt to start or expand a business. For young firms, access to credit for business growth can mean the difference between survival and failure. Equity crowdfunding is an innovative means of raising capital for businesses. Crowdfunding campaigns can give new business access to a large pool of investors. This brings huge benefits for marketing and increase provability of success of business and ROI, so it leads follow-on investment from Venture Capital and Angel investors. In Korea, the survival rate of startups and average growth rate of survivors is far lower than those of the U.S or other countries due to lack of funds for startup or early business growth. Equity crowdfunding can be a new funding source for venture or startups. It can increase startup and survival rate, in addition to the growth rate of survivors, resulting in decreased unemployment rate. In Korea, Equity crowdfunding will be available from 2016. Further study is needed to determine whether the impact of crowdfunding in Korea on job creation will be similar to its impact in the U.S.

• The Journal of Korean Academy of Prosthodontics
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• v.48 no.1
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• pp.61-68
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• 2010

Purpose: This article attempted to determine the factors affecting the preload and screw loosening. Methods: Available clinical studies from 1981 to 2008 from the PUBMED that presented screw loosening data and review articles regarding screw joint stability were evaluated. Eleven studies dealing the biomechanical principles of the screw mechanics were reviewed. Moreover, the results of our data were included. Results: The frequency of screw loosening was consequently reduced due to the advancement in torque tightening with torque wrench, screw material, coating technique for reducing the frictional force, and thread design, etc. If preload in the screw falls below a critical level, joint stability may be compromised, and the screw joint may fail clinically. The types of fatigue failure of screw were divided to adhesive wear, plastic deformation, and screw fracture. Conclusion: An optimum preload is essential to the success of the implant-abutment complex. To maintain optimum preload, using a torque wrench and re-tightening at recall time were needed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.12
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• pp.400-413
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• 2017

It is necessary for inmates released from prison to recover their career capital in order to function normally in society. Failure to adapt to the society may not only make them unhappy but could also aggravate social safety nets. Therefore, it is critical to examine the recovery of career capital. For this study, we conducted in-depth interviews of 10 rehabilitation recipients who were supported by Korea Rehabilitation Agency. For qualitative analysis, several career topics were analyzed, such as obstacles in recovering career capital, efforts in overcoming these obstacles, what is helpful for them to overcome the obstacles and what is required for them to adapt to the career life and others. Analysis results found that the rehabilitation beneficiaries suffered loses to their career capital due to their incarceration, suffered from the loss of pride and became despondent in the process of recovery of career capital due to the negative social perception toward their social self, fear of social stigma and devaluation of themselves. In addition, the fear of possible negative evaluation was a critical factor in making their social activities more challenging. Conversely, it was found that social support in the recovery process of career capital has a positive effect. In particular, emotional support from spouses, employers, family members and friends are the most positive factors. Concerning efforts at adapting to careers, it was found that an active, leading and positive attitude toward the career were critical, showing that positive evaluation and recognition in family and social relations and the experience of success in the career were positive elements in enhancing a sense of pride. In summary, it was found that in the recovery process of career capital, dysfunctional beliefs had a negative effect, while social support had a positive effect, on the recovery of career capital.