• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.23 no.4
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• pp.329-350
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• 2019

This paper examines individual and social strategies to form profitable cooperation networks. These two types of strategies measure network stability and efficiency that may not meet in a single network. We apply restrictions on knowledge flows (R&D spillovers) and links formation to integrate these benefits into structures that ensure high outcomes for both strategies. The results suggest that linking the spillovers to the firms' positions and restricting cooperation contribute to reducing the conflict between the individual and social strategies in the development of cooperative networks.

• Communications of the Korean Mathematical Society
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• v.13 no.4
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• pp.903-911
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• 1998

We show that if r $\leq$ 2, the average error of the Trapezoidal rule is proportional to $n^{-min{r＋l, 3}}$ where n is the number of mesh points on the interval [D, 1]. As a result, we show that the Trapezoidal rule with equally spaced points is optimal in the average case setting when r $\leq$ 2.

• The Journal of Korean Academy of Prosthodontics
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• v.38 no.5
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• pp.606-617
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• 2000

The purpose of this study was to measure the marginal fidelities and the fracture strength of IPS Empress $2^{(R)}\;and\;In-Ceram^{(R)}$ ceramic crowns. After constructed of 12 experimental dies for each group, ceramic crowns were fabricated on the metal master dies prepared on the maxillary right premolar Marginal gaps were measured on the specimen between the margin of each crown and finish-ing line of the metal master die by using stereo-microscope($SZ-ST^{(R)}$ Olympus, Japan) and all specimens were cemented on the metal master die with Bistite $II^{(R)}$ (Tokuyama soda Co, LTD., Japan) resin cement. Finally marginal gaps were measured again. To measure of the fracture strength, buccal incline on the functional cusp of specimens were loaded until the catastrophic failure occurred by using the AGS-1000 $D^{(R)}$(Shimadzu, Japan). The result of marginal fidelities and fracture strength were statistically analyzed with the SPSS version 8.0 programs. The results of this study were as follows : 1. No significant difference was found in the mean marginal fidelities and fracture strength between the IPS Empress $2^{(R)}\;and\;In-Ceram^{(R)}$. 2. In comparison of marginal fidelities between before and after cementation, there was significant difference(P<0.05). The IPS Empress 2 system was shown in this study that had good marginal fidelities and fracture strength compared to In-Ceram ceramics. Although this system was acceptable to clinical applications, the system still has to be considered long-term researches about marginal fidelities and fracture strength due to the lack of data about the clinical researches.

• The Journal of Korean Physical Therapy
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• v.28 no.5
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• pp.341-347
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• 2016

Purpose: The aim of the study was to investigate items of commonly used questionnaires that measure functioning status of persons with stroke and map to the International Classification of Functioning, Disability and Health (ICF). Methods: Eighty-six patients with stroke were recruited from 12 medical institutes for the study. Each item of the Modified Bathel Index (MBI), Stroke Impact Scale (SIS), Mini Mental Status Evaluation (MMSE) and SF-36 were examined and compared its concept with the ICF. Concept linking was performed by 10 health professionals independently. A field test was performed to assess its correlation between those of scales and their linked ICF category sets. Results: It was found that 11 items in MBI was linked to 14 ICF categories, whereas 27 items of MMSE had 10 categories of ICF linked. 60 items of SIS were to be linked with 35 ICF categories. Agreement between professionals in linking was found to be high: 97.5% for MBI items, 78.0%, 78.0%, and 74.8% for MMSE, SIS, and SF-36 respectively. Strong relationship was observed between measurement scales and linked ICF code sets (r=-0.76 for SIS, r=-0.78 for MBI, r=-0.47 for MMSE) whereas there was no relationship was found between SF-36 and its ICF code set (r=-0.06) from the field test. Conclusion: It was found that items of SIS, MMSE and MBI may be linked to ICF categories. Those of linking concept between clinical tools and the ICF could be helpful for clinical data standardization.

• Journal of Preventive Medicine and Public Health
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• v.34 no.1
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• pp.55-60
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• 2001

Objectives : The SERVQUAL scale is based on gap theory, which suggests the difference between consumers' expectations and the quality of the medical service actually received. However, problems in the implementation of the SERVQUAL scale have been identified by several researchers. Some researchers have proposed a simple performance-based measure (SERVPERF) or au exportation-controlled performance-based measure(Non-Diff) as alternatives to the SERVQUAL scale. On the basis of the theoretical concerns discussed, we examined the capability of each of the three scales(SERVQUAL, Non-Diff, SERVPERF) to explain variations in consumer satisfaction. Methods : Data was gathered from a self-administered questionnaire in a 430 bed hospital. Questionnaires evaluating medical services were distributed to 180 ambulatory patients. A total of 167 usable questionnaires were gathered. The questionnaire was composed of 10 expectation, performance and expectation-controlled performance items. In addition, overall satisfaction and purchase intention were measured. Results : Compared with the SERVQUAL scale, the Non-Diff and SERVPERF scales better explained the observed variations in consumer satisfaction(SERVOQUAL, $R^2=0.29;\;Non-Diff,\;R^2=0.51;\;SERVPERF,\;R^2=0.48$) and purchase intention(SERVQUAL, $R^2=0.22;\;Non-Diff,\;R^2=0.33;\;SERVPERF,\;R^2=0.34$). Conclusion : The maier conclusion from our study is that the Non-Diff and SERVPERF scales are more efficient in assessing consumer satisfaction than the SERVQUAL scale. Therefore we suggest that consumer satisfaction he measured by the Non-Diff or SEVPERF scales.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• v.4 no.4
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• pp.255-261
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• 2000

Experiments were carried out to measure the corrosion potential and current density variations in the polarization curves of polypropylene. In particular, the results were examined to identify those influences affecting the corrosion potential, such as temperature, pH, salt, and oxygen. The Tafel slope for the anodic dissolution was determined based on the polarization effect under various conditions. Furthermore, the optimum conditions for the most rapid transformation were establish based on a variety of conditions, including temperature, pH, corrosion rate, and resistance of corrosion potential. The second anodic current density peak and maximum passive current density were designated as the critical corrosion sensitivity(I(sub)r/I(sub)f). This I(sub)r/I(sub)f value was then used to measure the critical corrosion sensitivity of polypropylene. The potentiodynamic parameters of corrosion were obtained using a Tafel plot.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.16 no.2
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• pp.137-149
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• 2012

We propose an efficient method to measure the insurance risk of causality insurance companies by using the CreditRisk+ methodology. This method is superior to previous methods in several aspects. Its computation speed is very fast and the input data form is simple. It is able to aggregate both credit risk and insurance risk, so the insurance company can manage the risk in combined manner. In this paper, we propose a mathematical method to obtain the aggregate loss distribution of portfolios having correlation among products or business lines as a general case, and then suggest its implementation algorithm. Finally we apply this method to the real data from Korea Insurance Development Institute (KIDI) and discuss its availability to real applications.

• Journal of the Korean Institute of Landscape Architecture
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• v.22 no.4
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• pp.75-80
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• 1995

It is important to estimate the possibility of recovery in physiologically damaged woody plant. It is suggested that C.E.R(cambial electrical resistance) might be a useful method to predict the permanent wilting point. D/A and A/D converter can be used to measure the C.E.R and it took only 10-20 msec for a measurement and the values were stable during this study. A computer could be used for the continual measurement of C.E.R. There were very big daily changes of C.E.R. was changed according to the changes of indoor temperature, but the phase was slightly different. It is reasoned that daily changes in C.E.R. is induced by the changes of water potential and cambial thickness. It was difficult to detect the changes of C.E.R. caused by changes in soil moisture under high soil water potential. Under low soil water potential, the changes in soil moisture under high soil water potential. Under low soil water potential, the changes of C.E.R. can be detected. After wilting, C.E.R. is increased very rapidly. When C.E.R. is not decreased by watering, it will be permanent wilting point. But it takes several days to confirm the permanent wilting point. To predict the possibility of recovery from wilting, the values of C.E.R. have no meaning. But the changes of C.E.R. are significant. Therefore we can predict the permant wilting point in woody plant by monitoring the change of C.E.R. by the computer.

• The Pure and Applied Mathematics
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• v.8 no.1
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• pp.71-78
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• 2001

In 1984, Johnson[A bounded convergence theorem for the Feynman in-tegral, J, Math. Phys, 25(1984), 1323-1326] proved a bounded convergence theorem for hte Feynman integral. This is the first stability theorem of the Feynman integral as an $L(L_2 (\mathbb{R}^N), L_2(\mathbb{R}^{N}))$ theory. Johnson and Lapidus [Generalized Dyson series, generalized Feynman digrams, the Feynman integral and Feynmans operational calculus. Mem, Amer, Math, Soc. 62(1986), no 351] studied stability theorems for the Feynman integral as an $L(L_2 (\mathbb{R}^N), L_2(\mathbb{R}^{N}))$ theory for the functional with arbitrary Borel measure. These papers treat functionals which involve only a single integral. In this paper, we obtain the stability theorems for the Feynman integral as an $L(L_1 (\mathbb{R}^N), L_{\infty}(\mathbb{R}^{N}))$theory for the functionals which involve double integral with some Borel measures.

• STI Policy Review
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• v.9 no.1
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• pp.1-29
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• 2018

With the constant growth of R&D investment, it has been increasingly necessary to evaluate the effectiveness of R&D performance and there is a high emphasis on ensuring the accountability and effectiveness of R&D programs. The evaluation of performance of a firm is especially necessary in times of economic downturn to justify R&D investment. However, there is a marked shortage of clear guidelines as to where and how particular metrics are used to measure the output and outcome of R&D activity in firms. Many firms have difficulties in selecting appropriate indicators for their R&D and financial performances. To fill this gap, this article discusses and presents the findings from the literature in such a way that they become useful for researchers or managers who are in charge of measuring the R&D and business performances arising from innovation activities. Finally, based on the findings about metrics of R&D performance, this article proposes the hypothetical framework to investigate the relationship between technology forecasting, strategic technology planning, and business performance. The framework of this article will assist policy makers, universities, research institutes/national laboratories, and companies to enhance their decision making process in technology development.