• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.12
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• pp.3833-3838
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• 2009

This paper introduces a measurement system for mechanical properties of sport shoes using an industrial robot. The robot system used in this paper is a commercial Puma type robot system(FARA AT2 made by SAMSUNG Electronics) with 6 joints and the end-effector is modified to produce a human walking motion. After analyzing human walking with a high speed video camera, each joint angle of the robot system is extracted to be used in the robot system. By using this system, ground impact forces were measured during stepping motion with 3 different shoe specimens made of 3 different hardness outsoles, respectively. As other mechanical properties, both bending moments to bend the toe part of the same specimen shoes and pronation quantities during walking motion were measured as well. In the impact test with the same depth of deformation under the ground level, the effect of the outsole hardness was clearly appeared such that the harder outsole produces the higher ground reaction force. The bending test and the pronation test also show proportional increments in the bending stiffness and the moment Mx according to the outsole hardness. Throughout such experiments, the robot system has produced consistent results so that the system could be used in obtaining valuable informations for a shoe designing process.

• Journal of Korean Society of Water and Wastewater
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• v.26 no.5
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• pp.669-683
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• 2012

The water supply pipes are buried across wide range of areas, so it is hard to spot them using excavation and takes a large amount of expense. Thus, there is a high risk for direct research and application, accompanying many difficulties in implementation of them. Therefore, it is more economical and convenient to use indirect evaluation variables than direct evaluation of the buried pipes in assessing the degree of pipe deterioration. To assess the degree of pipe deterioration using the indirect evaluation variables, it should be done first to identify how and to what extent they affect the degree of deterioration. This study measured the evaluation variables for pipe deterioration using the pipe endoscope and analyzed the measurement results and the degree of impact on the pipes. In addition, this study attempted to evaluate the adequateness of the pipe deterioration evaluation using the indirect variables based on the analysis results. The evaluation variables measured through the pipe endoscope were the thickness of sediments, size of scale, degree of desquamation and condition of connections. For the indirect evaluation variables, the data such as the property data from GIS pipe network map as well as the material, diameter, age and pipe lining material of the pipe, road type, leakage frequency, average water velocity and water pressure using the leakage repair records was collected. Using the collected data, this study comparatively analyzed the indirect evaluation variables for the degree of pipe deterioration and the results from the pipe endoscope to choose appropriate variables for pipe deterioration evaluation and calculated the weights of the indirect variables on the degree of deterioration. The results showed that the order of the impact of indirect variables on deterioration was pipe age > pipe lining material > road type > leakage frequency > average water velocity with their weights of 0.45, 0.20, 0.15, 0.10, and 0.10, respectively. Conclusively, the results suggest that the measures of sediment thickness, scale size, degree of desquamation and condition of connections are appropriate for the evaluation of pipe deterioration and sufficient for the analysis of the impact of the indirect variables on deterioration.

• Journal of Environmental Impact Assessment
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• v.23 no.5
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• pp.323-336
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• 2014

Using hedonic price method, this paper analyzes the impact of restriction for water quality protection on property value with the officially announced price of reference land in the city of Namyangju in 2012 to evaluate Water Use Fee, based on beneficiary pays principle, levied on the downstream area of the Han River in Korea. The results from the regression analyses of the models used show that the double-log model is the preferred model in the case of Namyangju. Using the double-log model, the total compensation for the city of Namyangju is estimated to be 8.6 trillion won with 95% confidence interval between 4.4 trillion and 12.4 trillion won. Under the perpetuity compensation scheme at the discount rate of 10%, the estimated annual compensation is 0.9 trillion won with 95% confidence interval between 0.4 trillion and 1.2 trillion won. This is more than Water Use Fee collected in 2012 for the Han River, which is approximately 0.5 trillion won. Considering the size of the restricted area of the Paldang area, which is more than 18 times of that of Namyangju, the rate of Water Use Fee, which is based on beneficiary pays principle and imposed on the residents of the downstream area, needs to be increased to sufficiently compensate the economic loss caused to the upstream areas of the Han River in Korea.

• Applied Chemistry for Engineering
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• v.25 no.1
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• pp.90-95
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• 2014

Nylon66 extrudates as a function of the extrusion number were prepared by a twin screw extruder. Chemical structures, thermal properties, melt index, crystal structures, mechanical properties such as the tensile strength, elongation at break and impact strength, and rheological property were measured by FT-IR, $^1H$-NMR, melt indexer, DSC, TGA, XRD, universal tensile tester, Izod impact tester, and rheometer. FT-IR and $^1H$-NMR characterizations indicated that the number of extrusions did not affect the chemical structure. The decrease in the molecular weight was checked by the melt index of extrudates. There were no effects of the thermal history on the melting and degradation temperature. The tensile and impact strength and modulus were found to be similar, regardless of the number of extrusions, but the elongation decreased significantly. The complex viscosity of extrudates at low frequencies decreased with the extrusion number. No structural changes after extrusion were confirmed from the fact that there was no change in the slope and shape of G'-G" plot.

• Elastomers and Composites
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• v.38 no.3
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• pp.262-272
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• 2003

Maleic anhydride-grafted-polypropylene(PP-g-MA) were used as a blend component and a compatibilizer, respectively, for two reactive blends of polyamide 66(PA 66)PP-g-MA binary blends and PA 66/polypropylene(PP)/PP-g-MA ternary blends. The goal of this work was to investigate the property differences between binary and ternary blends. Tensile strength, flexural modulus, heat deflection temperature, impact strength, melt flow index, and the dependence of melt viscosity on the shear rate were examined. The impact strengths of binary blends were higher than those of ternary blends at all compositions, since the in situ synthesis of PP-g-PA 66 copolymer through the imide formation between the amine end group of PA 66 and the anhydride group of PP-g-MA gave the increase of molecular weight and was more popular in binary blends than in ternary blends. In case of ternary blends, most of the properties were superior to those of binary blends, owing to the better properties of PP compared with PP-g-MA. The toughened binary blends with 70/30(PA 66/PP-g-MA) and 80/20 ratios were not commercially applicable due to their poor processibility. So, the ternary blends which showed lower melt viscosities were recommended for the commercial applications.

• Korean small business review
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• v.43 no.1
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• pp.51-83
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• 2021

This study empirically examined how the technology innovation competence of the 4th Industrial Revolution Enterprises affects management performance. It also analyzed whether there would be any difference in business performance between the 4th Industrial Revolution Enterprises and the non-4th Industrial Revolution Enterprises. The samples for analysis were analyzed using in-situ data of 2,543 enterprises classified as technical innovation enterprises and the 4th Industrial Revolution Enterprises through Korea Technology Finance Corporation's in-house technical evaluation. Variables for technology innovation competence were analyzed using variables such as the size of manpower of research and development, the level of research and development organizations, the number of intellectual property rights, the ratio of intangible assets, the amount of knowledge properties, the amount of research and development investment, and the intensiveness degree of research and development. In terms of the impact of the 4th Industrial Revolution Enterprises' technology innovation competence on business performance, all factors except for the level of research and development organizations were found to affect business performance, which supported the study hypothesis. In particular, it was confirmed that the amount of knowledge properties has had a relatively greater impact on business performance. In addition, the average comparative analysis between the 4th Industrial Revolution Enterprises and the non-4th Industrial Revolution Enterprises confirmed that the 4th Industrial Revolution Enterprises conducted higher values in the business performance.

• Health Policy and Management
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• v.32 no.4
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• pp.347-355
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• 2022

Background: Since November 2019, long-term care hospitals have been able to provide patients with discharging programs to support the elderly in the community. This study aimed to identify both patient- and hospital-level factors that affect successful community discharge from long-term care hospitals. Methods: A multilevel logistic regression model was performed using hospitals as a clustering unit. The dependent variable was whether a patient stayed in the community for at least 30 days after discharge from a long-term care hospital. As for the patient-level independent variables, an agreement between a patient and the family about discharge, length of hospital stay, patient category, and residence at discharge were included. The number of beds and the ratio of long-stay patients were selected for the hospital-level factors. The sample size was 1,428 patients enrolled in the discharging program from November 2019 to December 2020. Results: The number of patients who were discharged to the community and stayed at least for 30 days was 532 (37.3%). The intraclass correlation coefficient was 22.9%, indicating that hospital-level factors had a significant impact on successful community discharge. The odds ratio (OR) of successful community discharge increased by 1.842 times when the patients and their families agreed on discharge. The ORs also increased by 3.020 or 2.681 times, respectively when the patients planned to discharge to their own house or their child's house compared to those who didn't have a plan for residence at discharge. The ORs increased by 1.922 or 2.250 times when the hospitals were owned by corporate or private property compared to publicly owned hospitals. The ORs decreased by 0.602 or 0.520 times when the hospital was sized over 400 beds or located in small and medium-sized cities compared to less than 200 bedded hospitals or located in metropolitan cities. Conclusion: The results of the study showed that the patients' and their family's willingness for discharge had a great impact on successful community discharge and the hospital-level factors played a significant role in it. Therefore, it is important to acknowledge and support long-term care hospitals to involve active in the patient discharge planning process.

• Journal of the Korean GEO-environmental Society
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• v.13 no.9
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• pp.5-16
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• 2012

In the case of using the soil materials created by cutting in-situ ground directly without adjusting particle size, it is recommendable to seek the compaction property or material constant required for filling design or density control through indoor test, and many studies on this subject have been carried out during that time. The researches conducted during that time, however, were focused on the mixed materials with different diameters that exist in a natural condition. There has been no study conducted using coal fly ash that is by-product of the thermal power plant that is actively considered as the building materials. Therefore, this study was aimed at implementing compaction test and examining the basic engineering property in order to explore the influence of crushing the particles through compacting the admixture of crushed stone and coal fly ash produced from thermal power plant on its engineering property, and then the impact of the admixture volume of each material on compaction property and material property by conducting the One-Dimensional Compression Test. As result of compaction test, the optimum moisture ratio of coal fly ash was shown to be approx. 23%. As result of compaction test in accordance with the mixed ratio of coal fly ash and crushed stone under the same compaction energy and moisture ratio, dry unit weight tended to drop when the mixed ratio of coal fly ash exceeded 30%, while it reached approx. $1.81gf/cm^3$ when the mixed ratio was 30%. As result of One-Dimensional Compression Test in accordance with the mixed ratio of crushed stone and coal fly ash, the change in void ratio by particle crushing was at the highest level in the case of coal fly ash 100%, while the lowest level in the case of crushed stone 100%. In the case of mixed materials of crushed stone and coal fly ash, compression index was at the lowest level in case of coal fly ash 30%, and therefore this ratio of mixed material was judged to be the most stable from an engineering aspect.

• Journal of the Korean Society for Marine Environment & Energy
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• v.13 no.3
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• pp.187-197
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• 2010

Carbon dioxide Capture and Storage(CCS) is regarded as one of the most promising options to response climate change. CCS is a three-stage process consisting of the capture of carbon dioxide($CO_2$), the transport of $CO_2$ to a storage location, and the long term isolation of $CO_2$ from the atmosphere for the purpose of carbon emission mitigation. Up to now, process design for this $CO_2$ marine geological storage has been carried out mainly on pure $CO_2$. Unfortunately the $CO_2$ mixture captured from the power plants and steel making plants contains many impurities such as $N_2$, $O_2$, Ar, $H_2O$, $SO_2$, $H_2S$. A small amount of impurities can change the thermodynamic properties and then significantly affect the compression, purification, transport and injection processes. In order to design a reliable $CO_2$ marine geological storage system, it is necessary to analyze the impact of these impurities on the whole CCS process at initial design stage. The purpose of the present paper is to compare and analyse the relevant physical property models including BWRS, PR, PRBM, RKS and SRK equations of state, and NRTL-RK model which are crucial numerical process simulation tools. To evaluate the predictive accuracy of the equation of the state for $CO_2-SO_2$ mixture, we compared numerical calculation results with reference experimental data. In addition, optimum binary parameter to consider the interaction of $CO_2$ and $SO_2$ molecules was suggested based on the mean absolute percent error. In conclusion, we suggest the most reliable physical property model with optimized binary parameter in designing the $CO_2-SO_2$ mixture marine geological storage process.

• Journal of Intelligence and Information Systems
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• v.19 no.3
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• pp.127-139
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• 2013

With an advent of recent knowledge-based society, the interest in intellectual property has increased. Firms have tired to result in productive outcomes through continuous innovative activity. Especially, ICT firms which lead high-tech industry have tried to manage intellectual property more systematically. Firm's interest in the patent has increased in order to manage the innovative activity and Knowledge property. The patent involves not only simple information but also important values as information of technology, management and right. Moreover, as the patent has the detailed contents regarding technology development activity, it is regarded as valuable data. The patent which reflects technology spread and research outcomes and business performances are closely interrelated as the patent is considered as a significant the level of firm's innovation. As the patent information which represents companies' intellectual capital is accumulated continuously, it has become possible to do quantitative analysis. The advantages of patent in the related industry information and it's standardize information can be easily obtained. Through the patent, the flow of knowledge can be determined. The patent information can analyze in various levels from patent to nation. The patent information is used to analyze technical status and the effects on performance. The patent which has a high frequency of citation refers to having high technological values. Analyzing the patent information contains both citation index analysis using the number of citation and network analysis using citation relationship. Network analysis can provide the information on the flows of knowledge and technological changes, and it can show future research direction. Studies using the patent citation analysis vary academically and practically. For the citation index research, studies to analyze influential big patent has been conducted, and for the network analysis research, studies to find out the flows of technology in a certain industry has been conducted. Social network analysis is applied not only in the sociology, but also in a field of management consulting and company's knowledge management. Research of how the company's network position has an impact on business performances has been conducted from various aspects in a field of network analysis. Social network analysis can be based on the visual forms. Network indicators are available through the quantitative analysis. Social network analysis is used when analyzing outcomes in terms of the position of network. Social network analysis focuses largely on centrality and structural holes. Centrality indicates that actors having central positions among other actors have an advantage to exert stronger influence for exchange relationship. Degree centrality, betweenness centrality and closeness centrality are used for centrality analysis. Structural holes refer to an empty place in social structure and are defined as efficiency and constraints. This study stresses and analyzes firms' network in terms of the patent and how network characteristics have an influence on business performances. For the purpose of doing this, seventy-four ICT companies listed in S&P500 are chosen for the sample. UCINET6 is used to analyze the network structural characteristics such as outdegree centrality, betweenness centrality and efficiency. Then, regression analysis test is conducted to find out how these network characteristics are related to business performance. It is found that each network index has significant impacts on net income, i.e. business performance. However, it is found that efficiency is negatively associated with business performance. As the efficiency increases, net income decreases and it has a negative impact on business performances. Furthermore, it is shown that betweenness centrality solely has statistically significance for the multiple regression analysis with three network indexes. The patent citation network analysis shows the flows of knowledge between firms, and it can be expected to contribute to company's management strategies by analyzing company's network structural positions.