• The Journal of Korean Academy of Prosthodontics
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• v.43 no.4
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• pp.528-543
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• 2005

Statement of problem: Repeated delivery and removal of abutment cause some changes such as wear, scratch or defect of hexagonal structure. It may increase the value of rotational freedom(RF) between hexagonal structures. Purpose: The purpose of this study was to evaluate surface changes and rotational freedom between the external hexagon of the implant fixture and internal hexagon of abutment after repeated delivery and removal under SEM and toolmaker's microscope. Materials and methods: Implant systems used for this study were 3i and Avana. Seven pail's of implant fixture, abutment and abutment screws for each system were selected and all fixtures were perpendicularly mounted in liquid unsaturated polyesther with dental surveyor. Each one was embedded beneath the platform of fixture. Surfaces of hexagonal structure before repeated closing and opening of abutment were observed using SEM and rotational freedom was measured by using toolmaker's microscope. Each abutment was secured to the implant future by each abutment screw with recommended torque value using a digital torque controller and was repeatedly delivered and removed by 20 times respectively. After experiment, evaluation for the change of hexagonal structures and measurement of rotational freedom were performed. Result : The results were as follows; 1. Wear of contact area between implant fixture and abutment was considerable in both 3i and Avana system. Scratches and defects were frequently observed at the line-angle of hexagonal structures of implant fixture and abutment. 2. In the SEM view of the external hexagon of implant fixture, the point-angle areas at the corner edge of hexagon were severely worn out in both systems. It was more notable in the case of 3i systems than in that of Avana systems. 3. In the SEM view of the internal hexagon of abutment, Gingi-Hue abutment of 3i systems showed severe wear in micro-stop contacts that were machined into the corners to prevent rotation and cemented abutment of Avana systems showed wear in both surface area adjacent to the corner mating with external hexagon of implant fixture. 4 The mean values of rotational freedom between the external hexagon of the implant fixture and internal hexagon of abutment were 0.48$\pm$0.04$^{\circ}$ in pre-tested 3i systems and 1.18$\pm$0.25$^{\circ}$ after test, and 1.80$\pm$0.04$^{\circ}$ in pre-tested Avana systems and 2.61$\pm$0.16$^{\circ}$ after test. 5. Changes of rotational freedom after test shouted statistical)y a significant increase in both 3i and Avana systems(P<0.05, paired t-test). 6. Statistically, there was no significant difference between amount of increase in the rotational freedom of 3i systems and amount of increase in that of Avana ones(P>0.05, unpaired t-test). Conclusion: Conclusively, it was considered that repeated delivery and remove of abutment by 20 times would not have influence on screw joint stability. However, it caused statistically the significant change of rotational freedom in tested systems. Therefore, it is suggested that repeated delivery and remove of abutment should be minimal as possible as it could be and be done carefully Additionally, it is suggested that the means or treatment to prevent the wear of mating components should be devised.

• Tunnel and Underground Space
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• v.30 no.4
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• pp.382-393
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• 2020

The engineered barrier system of high-level radioactive waste disposal must maintain its performance in the long term, because it must play a role in slowing the rate of leakage to the surrounding rock mass even if a radionuclide leak occurs from the canister. In particular, it is very important to clarify gas dilation flow phenomenon clearly, that occurs only in a medium containing a large amount of clay material such as a bentonite buffer, which can affect the long-term performance of the bentonite buffer. Accordingly, DECOVALEX-2019 Task A was conducted to identify the hydraulic-mechanical mechanism for the dilation flow, and to develop and verify a new numerical analysis technique for quantitative evaluation of gas migration phenomena. In this study, based on the conventional two-phase flow and mechanical behavior with effective stresses in the porous medium, the hydraulic-mechanical model was developed considering the concept of damage to simulate the formation of micro-cracks and expansion of the medium and the corresponding change in the hydraulic properties. Model verification and validation were conducted through comparison with the results of 1D and 3D gas injection tests. As a result of the numerical analysis, it was possible to model the sudden increase in pore water pressure, stress, gas inflow and outflow rate due to the dilation flow induced by gas pressure, however, the influence of the hydraulic-mechanical interaction was underestimated. Nevertheless, this study can provide a preliminary model for the dilation flow and a basis for developing an advanced model. It is believed that it can be used not only for analyzing data from laboratory and field tests, but also for long-term performance evaluation of the high-level radioactive waste disposal system.

• Journal of Bio-Environment Control
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• v.15 no.2
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• pp.125-137
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• 2006

Pleurotus eryngii is one of the most promising mushrooms produced on the domestic farms. The quality as well as quantity of Eryngii is sensitively affected by micro climate factors such as temperature, relative humidity, $CO_2$ concentration, and light intensity. To safely produce high-quality Eryngii all the yew round, it is required that the environmental factors be carefully controlled by well designed structures equipped with various facilities and control systems. At the commercial mushroom cultivation houses of permanent frame type (A, B), this study was carried out to find out reasonable range of each environmental factor and yield together with economic and safe structures influencing on the optimal productivity of Eryngii. This experiment was conducted for about two-year ken Nov. 2003 to Dec. 2005 in cultivation house. Ambient temperature during the experiment period was not predominantly different from that of a normal year. The capacity of the hot water boiler and the piping systems were not enough. Because the capacity of electric heater and air circulation were not enough, air temperatures in cultivation house before improvement of system were maintained somewhat lower than setting temperature, and maximum air temperature difference between the upper and lower growth stage during a heating time period was about 5.1. But the air temperatures after system improvement were maintained within the limits range of setting temperature without happening stagnant of air. Air temperature distribution was generally distributed uniform. Relative humidity in cultivation house before , improvement was widely ranged about $44{\sim}100%$. But as the relative humidity after improvement was ranged approximately $80{\sim}100%$, it was maintained within the range of relative humidity recommended. And $CO_2$ concentration was maintained about $400{\sim}3,300mg{\cdot}L^{-1}$ range. The illuminance in cultivation house was widely distributed in accordance with position, and it was maintained lower than the recommended illuminance range $100{\sim}200lx$. The acidity of midium was some lower range than the recommend acidity range of pH $5.5{\sim}6.5$. The yield was relatively ununiform. In case of bottle capacity of 1,300cc, the mushroom of the lowest grade was less than 3%. The consumption electric energy was quite different according to the cultivation season. The electric energy consumed during heating season was much more than that of cooling season.

• Tuberculosis and Respiratory Diseases
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• v.48 no.6
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• pp.837-852
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• 2000

Backgrounds : Today, tuberculosis cannot only be cured medically, but also controlled by public health. Despite the overall worldwide decline in tuberculosis, the disease continues to be a significant problem among developing countries and in the slums of large cities in some industrialized countries. Particularly, this communicable disease has come into the public health spotlight because of its resurgence in the 1990's. our country has been operating the Korean National Tuberculosis Control Program since 1962, focusing around public health centers. Therefore, this study aims to compare the effectiveness of tuberculosis control activities, one of the major public health activities in Korea, by producing indexes, such as the yearly registration rate per 100,000 population and treatment compliance of tuberculosis on in small areas (communities). Methods : This work was accomplished by constructing a time-series analytic model using data from "1980~2000: the Yearly Statistical Report" with patient registry data of 234 City. County. District public health centers and by identifying the factors influencing the tuberculosis indexes. Results : The trends of pulmonary tuberculosis positive point prevalence and pulmonary tuberculosis negative point prevalence on X-ray screening have declined steadily, beginning in 1981 and continuing to 1998 by region (city, county, district). Although the tuberculosis mortality rate steadily shows a declining trend by year and region, but Korea still ranks first among 29 OECD countries in 1998, with a tuberculosis mortality rate of 7.1 per 100,000 persons, according to the time-series analysis for fatal diseases. Conclusion : The results of the study will form the fundamental basis of future regional health care planning and the Korean Tuberculosis Surveillance System on 2000. Since the implementation of local autonomy through the Local Health Act of 1995, it has now become vita1 for each city, county, district public health centers to determine its own priorities for relevant health care management, including budget allocation and program goals.

• Tuberculosis and Respiratory Diseases
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• v.44 no.1
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• pp.69-84
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• 1997

Background : Although the overall prognosis of patients with lung cancer is poor, highly effective treatment exists for the small subset of patients with early lung cancer(carcinoma in situ/micro- invasive cancer). But very few patients have benefit from them because these lesions are difficult to detect and localize with conventional white-light bronchoscopy. To overcome this problem, a Lung Imaging Fluorescence Endoscopic device(LIFE) was developed to detect and clearly delineate the exact location and extent of premalignant and early lung cancer lesions using differences in tissue autofluorescence. Purpose : The purpose of this study was to determine the difference of sensitivity and specificity in detecting dysplasia and carcinoma between fluorescence imaging and conventional white light bronchoscopy. Material and Methods : 35 patients (16 with abnormal chest X-ray, 2 with positive sputum study, 2 with undiagnosed pleural effusion, 15 with respiratory symptom) have been examined by LIFE imaging system. After a white light bronchoscopy, the patients were submitted to fluorescence bronchoscopy and the findings of both examinations have been classified in 3 categories(class I, II, III). From of all class n and III sites, 79 biopsy specimens have been collected for histologic examination: a comparison between histologic results and white light or fluorescence bronchoscopy has been performed for assessing sensitivity and specificity of the two methods. Results : 1) Total 79 sires in 35 patients were examined. Histology demonstrated 8 normal mucosa, 21 hyperplasia, 23 dysplasia, and 27 microinvasive and invasive carcinoma. 2) The sensitivity of white light or fluorescence bronchoscopy in detecting dysplasia was 60.9% and 82.6%, respectively. 3) The results of this study showed 70.3 % sensitivity for microinvasive or invasive carcinoma with LIFE system, versus 100% sensitivity for white light in 27 cases of carcinoma. The false negative study of LIFE system was 8 cases(3 adenocarcinoma and 5 small cell carcinoma), which were infiltrated in submucosal area and had normal epithelium. Conclusion : To improve the ability 10 diagnose and stage more accurately, fluorescence imaging may become an important adjunct to conventional bronchoscopic examination because of its high detection rate of premalignant and malignant epithelial lesion. But. it has limitation to detect in submucosal infiltrating carcinoma.

• KDI Journal of Economic Policy
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• v.13 no.4
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• pp.91-116
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• 1991

Market liberalization progressing simultaneously with high and rapidly rising domestic wages has created an adverse business environment for domestic firms. Korean firms are losing their international competitiveness in comparison to firms from LDC(Less Developed Countries) in low-tech industries. In high-tech industries, domestic firms without government protection (which is impossible due to the liberalization policy and the current international status of the Korean economy) are in a disadvantaged position relative to firms from advanced countries. This paper examines the division of roles between the private sector and the government in order to achieve a successful structural adjustment, which has become the impending industrial policy issue caused by high domestic wages, on the one hand, and the opening of domestic markets, on the other. The micro foundation of the economy-wide structural adjustment is actually the restructuring of business portfolios at the firm level. The firm-level business restructuring means that firms in low-value-added businesses or with declining market niches establish new major businesses in higher value-added segments or growing market niches. The adjustment of the business structure at the firm level can only be accomplished by accumulating firm-specific managerial assets necessary to establish a new business structure. This can be done through learning-by-doing in the whole system of management, including research and development, manufacturing, and marketing. Therefore, the voluntary cooperation among the people in the company is essential for making the cost of the learning process lower than that at the competing companies. Hence, firms that attempt to restructure their major businesses need to induce corporate-wide participation through innovations in organization and management, encourage innovative corporate culture, and maintain cooperative labor unions. Policy discussions on structural adjustments usually regard firms as a black box behind a few macro variables. But in reality, firm activities are not flows of materials but relationships among human resources. The growth potential of companies are embodied in the human resources of the firm; the balance of interest among stockholders, managers, and workers of the company' brings the accumulation of the company's core competencies. Therefore, policymakers and economists shoud change their old concept of the firm as a technological black box which produces a marketable commodities. Firms should be regarded as coalitions of interest groups such as stockholders, managers, and workers. Consequently the discussion on the structural adjustment both at the macroeconomic level and the firm level should be based on this new paradigm of understanding firms. The government's role in reducing the cost of structural adjustment and supporting should the creation of new industries emphasize the following: First, government must promote the competition in domestic markets by revising laws related to antitrust policy, bankruptcy, and the promotion of small and medium-sized companies. General consensus on the limitations of government intervention and the merit of deregulation should be sought among policymakers and people in the business world. In the age of internationalization, nation-specific competitive advantages cannot be exclusively in favor of domestic firms. The international competitiveness of a domestic firm derives from the firm-specific core competencies which can be accumulated by internal investment and organization of the firm. Second, government must build up a solid infrastructure of production factors including capital, technology, manpower, and information. Structural adjustment often entails bankruptcies and partial waste of resources. However, it is desirable for the government not to try to sustain marginal businesses, but to support the diversification or restructuring of businesses by assisting in factor creation. Institutional support for venture businesses needs to be improved, especially in the financing system since many investment projects in venture businesses are highly risky, even though they are very promising. The proportion of low-value added production processes and declining industries should be reduced by promoting foreign direct investment and factory automation. Moreover, one cannot over-emphasize the importance of future-oriented labor policies to be based on the new paradigm of understanding firm activities. The old laws and instititutions related to labor unions need to be reformed. Third, government must improve the regimes related to money, banking, and the tax system to change business practices dependent on government protection or undesirable in view of the evolution of the Korean economy as a whole. To prevent rational business decisions from contradicting to the interest of the economy as a whole, government should influence the business environment, not the business itself.

• Journal of the Korean Vacuum Society
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• v.17 no.1
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• pp.16-22
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• 2008

We studied plasma etching of polycarbonate in $O_2/SF_6$, $O_2/N_2$ and $O_2/CH_4$. A capacitively coupled plasma system was employed for the research. For patterning, we used a photolithography method with UV exposure after coating a photoresist on the polycarbonate. Main variables in the experiment were the mixing ratio of $O_2$ and other gases, and RF chuck power. Especially, we used only a mechanical pump for in order to operate the system. The chamber pressure was fixed at 100 mTorr. All of surface profilometry, atomic force microscopy and scanning electron microscopy were used for characterization of the etched polycarbonate samples. According to the results, $O_2/SF_6$ plasmas gave the higher etch rate of the polycarbonate than pure $O_2$ and $SF_6$ plasmas. For example, with maintaining 100W RF chuck power and 100 mTorr chamber pressure, 20 sccm $O_2$ plasma provided about $0.4{\mu}m$/min of polycarbonate etch rate and 20 sccm $SF_6$ produced only $0.2{\mu}m$/min. However, the mixed plasma of 60 % $O_2$ and 40 % $SF_6$ gas flow rate generated about $0.56{\mu}m$ with even low -DC bias induced compared to that of $O_2$. More addition of $SF_6$ to the mixture reduced etch of polycarbonate. The surface roughness of etched polycarbonate was roughed about 3 times worse measured by atomic force microscopy. However examination with scanning electron microscopy indicated that the surface was comparable to that of photoresist. Increase of RF chuck power raised -DC bias on the chuck and etch rate of polycarbonate almost linearly. The etch selectivity of polycarbonate to photoresist was about 1:1. The meaning of these results was that the simple capacitively coupled plasma system can be used to make a microstructure on polymer with $O_2/SF_6$ plasmas. This result can be applied to plasma processing of other polymers.

• Journal of Distribution Research
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• v.15 no.3
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• pp.1-34
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• 2010

Introduction The purpose of this research is to develop overall model which involves the effect of ongoing support services by franchisor on franchisee's relationship quality(trust, satisfaction, and commitment) and business performance(financial and non-financial performance), and to investigate the relationships among trust, satisfaction, commitment, financial and non-financial performance. This study also suggests franchise business or franchise system should be based on long-term orientation between franchisor and franchisee rather than short-term orientation, or transactional relationship, and proposes the most effective way of providing on-going support services by franchisor with franchisee thru symbiotic relationship among franchisor and franchisee Research Model and Hypothesis The research model as Figure 1 shows the variables on-going support services which affect the relationship quality between franchisor and franchisee such as trust, satisfaction, and commitment, and also analyze the effects of relationship quality on business performance including financial and non-financial performance We established 12 hypotheses to test as follows; Relationship between on-going support services and trust H1: On-going support services factors (product category & price, logistics service, promotion, information providing & problem solving capability, supervisor's support, and education & training support) have positive effect on franchisee's trust. Relationship between on-going support services and satisfaction H2: On-going support services factors (product category & price, logistics service, promotion, information providing & problem solving capability, supervisor's support, and education & training support) have positive effect on franchisee's satisfaction. Relationship between on-going support services and commitment H3: On-going support services factors (product category & price, logistics service, promotion, information providing & problem solving capability, supervisor's support, and education & training support) have positive effect on franchisee's commitment. Relationship among relationship quality: trust, satisfaction, and commitment H4: Franchisee's trust has positive effect on franchisee's satisfaction. H5: Franchisee's trust has positive effect on franchisee's commitment. H6: Franchisee's satisfaction has positive effect on franchisee's commitment. Relationship between relationship quality and business performance H7: Franchisee's trust has positive effect on franchisee's financial performance. H8: Franchisee's trust has positive effect on franchisee's non-financial performance. H9: Franchisee's satisfaction has positive effect on franchisee's financial performance. H10: Franchisee's satisfaction has positive effect on franchisee's non-financial performance. H11: Franchisee's commitment has positive effect on franchisee's financial performance. H12: Franchisee's commitment has positive effect on franchisee's non-financial performance. Method The on-going support services were defined as an organized system of continuous supporting services by franchisor for the purpose of satisfying the expectation of franchisee based on long-term orientation and classified into six constructs such as product category & price, logistics service, promotion, providing information & problem solving capability, supervisor's support, and education & training support. The six constructs were measured agreement using a 7-point Likert-type scale (1 = strongly disagree to 7 = strongly agree)as follows. The product category & price was measured by four items: menu variety, price of food material provided by franchisor, and support for developing new menu. The logistics service was measured by six items: distribution system of franchisor, return policy for provided food materials, timeliness, inventory control level of franchisor, accuracy of order, and flexibility of emergency order. The promotion was measured by five items: differentiated promotion activities, brand image of franchisor, promotion effect such as customer increase, long-term plan of promotion, and micro-marketing concept in promotion. The providing information & problem solving capability was measured by information providing of new products, information of competitors, information of cost reduction, and efforts for solving problems in franchisee's operations. The supervisor's support was measured by supervisor operations, frequency of visiting franchisee, support by data analysis, processing the suggestions by franchisee, diagnosis and solutions for the franchisee's operations, and support for increasing sales in franchisee. Finally, the of education & training support was measured by recipe training by specialist, service training for store people, systemized training program, and tax & human resources support services. Analysis and results The data were analyzed using Amos. Figure 2 and Table 1 present the result of the structural equation model. Implications The results of this research are as follows: Firstly, the factors of product category, information providing and problem solving capacity influence only franchisee's satisfaction and commitment. Secondly, logistic services and supervising factors influence only trust and satisfaction. Thirdly, continuing education and training factors influence only franchisee's trust and commitment. Fourthly, sales promotion factor influences all the relationship quality representing trust, satisfaction, and commitment. Fifthly, regarding relationship among relationship quality, trust positively influences satisfaction, however, does not directly influence commitment, but satisfaction positively affects commitment. Therefore, satisfaction plays a mediating role between trust and commitment. Sixthly, trust positively influence only financial performance, and satisfaction and commitment influence positively both financial and non-financial performance.

• Journal of Venture Innovation
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• v.5 no.1
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• pp.107-127
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• 2022

Global challenges such as the corona pandemic, climate change and the war-on-tech ensure that the demand who the technologies of the future develops and monitors prominently for will be on the agenda. Development of, and applications in, agrifood, biotech, high-tech, medtech, quantum, AI and photonics are the basis of the future earning capacity of the Netherlands and contribute to solving societal challenges, close to home and worldwide. To be like the Netherlands and Europe a strategic position in the to obtain knowledge and innovation chain, and with it our autonomy in relation to from China and the United States insurance, clear choices are needed. Brainport Eindhoven: Building on Philips' knowledge base, there is create an innovative ecosystem where more than 7,000 companies in the High-tech Systems & Materials (HTSM) collaborate on new technologies, future earning potential and international value chains. Nearly 20,000 private R&D employees work in 5 regional high-end campuses and for companies such as ASML, NXP, DAF, Prodrive Technologies, Lightyear and many others. Brainport Eindhoven has a internationally leading position in the field of system engineering, semicon, micro and nanoelectronics, AI, integrated photonics and additive manufacturing. What is being developed in Brainport leads to the growth of the manufacturing industry far beyond the region thanks to chain cooperation between large companies and SMEs. South-Holland: The South Holland ecosystem includes companies as KPN, Shell, DSM and Janssen Pharmaceutical, large and innovative SMEs and leading educational and knowledge institutions that have more than Invest €3.3 billion in R&D. Bearing Cores are formed by the top campuses of Leiden and Delft, good for more than 40,000 innovative jobs, the port-industrial complex (logistics & energy), the manufacturing industry cluster on maritime and aerospace and the horticultural cluster in the Westland. South Holland trains thematically key technologies such as biotech, quantum technology and AI. Twente: The green, technological top region of Twente has a long tradition of collaboration in triple helix bandage. Technological innovations from Twente offer worldwide solutions for the large social issues. Work is in progress to key technologies such as AI, photonics, robotics and nanotechnology. New technology is applied in sectors such as medtech, the manufacturing industry, agriculture and circular value chains, such as textiles and construction. Being for Twente start-ups and SMEs of great importance to the jobs of tomorrow. Connect these companies technology from Twente with knowledge regions and OEMs, at home and abroad. Wageningen in FoodValley: Wageningen Campus is a global agri-food magnet for startups and corporates by the national accelerator StartLife and student incubator StartHub. FoodvalleyNL also connects with an ambitious 2030 programme, the versatile ecosystem regional, national and international - including through the WEF European food innovation hub. The campus offers guests and the 3,000 private R&D put in an interesting programming science, innovation and social dialogue around the challenges in agro production, food processing, biobased/circular, climate and biodiversity. The Netherlands succeeded in industrializing in logistics countries, but it is striving for sustainable growth by creating an innovative ecosystem through a regional industry-academic research model. In particular, the Brainport Cluster, centered on the high-tech industry, pursues regional innovation and is opening a new horizon for existing industry-academic models. Brainport is a state-of-the-art forward base that leads the innovation ecosystem of Dutch manufacturing. The history of ports in the Netherlands is transforming from a logistics-oriented port symbolized by Rotterdam into a "port of digital knowledge" centered on Brainport. On the basis of this, it can be seen that the industry-academic cluster model linking the central government's vision to create an innovative ecosystem and the specialized industry in the region serves as the biggest stepping stone. The Netherlands' innovation policy is expected to be more faithful to its role as Europe's "digital gateway" through regional development centered on the innovation cluster ecosystem and investment in job creation and new industries.

• The Journal of Korean Academy of Prosthodontics
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• v.46 no.4
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• pp.343-350
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• 2008

Purpose: The purpose of this study was to spectrophotometrically evaluate the shade difference between of maxillary and mandibular anterior teeth in the Korean by the standard of vita classical shade guide using $SpectroShade^{TM}$. Material and methods: In this study, the shades of healthy anterior teeth were examined and analyzed using the digital shade analysis of $SpectroShade^{TM}$. This study examined 80 individuals in their twenties, thirties, fourties, fifities ages and 40 males and 40 females, presenting 12 healthy, unrestored maxillary and mandibular anterior teeth. Tooth brushing and oral prophylaxis were performed prior to evaluation. The $SpectroShade^{TM}$ was used to acquire images of the 12 maxillary and mandibular anterior teeth. These images were analyzed using $SpectroShade^{TM}$ Software, and shade maps of each tooth were acquired. The shade difference of upper and lower, and gender differences and ages difference were investigated and analyzed with CIE $L^{*}a^{*}b^{*}$ color order system. One-Way ANOVA test was used to find out if there were significant differences between groups tested and Sheffe multiple comparison was used to identify where the differences were. Results: 1. Shade differences were significant (P < .05) between maxillary and mandibular central incisor, lateral incisor, canine. 2. No significant differences in shade distribution were seen between lateral incisors and central incisors. 3. Canine's shade difference were more significant than central incisor's and lateral incisors's. 4. No significant differences in shade distribution were seen between genders in maxillary and mandibulr central incisor, lateral incisor, canine. 5. No significant differences in shade distribution were seen in order of years in maxillary and mandibulr central incisor, lateral incisor, canine. Conclusions: The results of this study show that 1. Shade difference was founded in maxillary and mandibular anterior teeth and ${\Delta}E^{*}$ value was more than 2.0. 2. Canine's shade difference were more significant than central incisor's and lateral incisors's and between central incisors and lateral incisors shade differences were no significant. 3. No significant differences in shade distribution were seen between genders in maxillary and mandibular anterior teeth. 4. No significant differences in shade distribution were seen in order of years grade in maxillary and mandibular anterior teeth.