• International Journal of Fluid Machinery and Systems
• /
• v.4 no.3
• /
• pp.317-323
• /
• 2011

Mini centrifugal pumps having a diameter smaller than 100mm are employed in many fields; automobile radiator pump, ventricular assist pump, cooling pump for electric devices and so on. Further, the needs for mini centrifugal pumps would become larger with the increase of the application of it for electrical machines. It is desirable that the mini centrifugal pump design be as simple as possible as precise manufacturing is required. But the design method for the mini centrifugal pump is not established because the internal flow condition for these small-sized fluid machines is not clarified and conventional theory is not suitable for small-sized pumps. Therefore, we started research on the mini centrifugal pump for the purpose of development of high performance mini centrifugal pumps with simple structure. Three types of rotors with different outlet angles are prepared for an experiment. The performance tests are conducted with these rotors in order to investigate the effect of the outlet angle on performance and internal flow condition of mini centrifugal pumps. In addition to that, the blade thickness is changed because blockage effect in the mini centrifugal pump becomes relatively larger than that of conventional pumps. On the other hand, a three dimensional steady numerical flow analysis is conducted with the commercial code (ANSYS-Fluent) to investigate the internal flow condition. It is clarified from the experimental results that head of the mini centrifugal pump increases according to the increase of the blade outlet angle and the decrease of the blade thickness. In the present paper, the performance of the mini centrifugal pump is shown and the internal flow condition is clarified with the results of the experiment and the numerical flow analysis. Furthermore, the effects of the blade outlet angle and the blade thickness on the performance are investigated and the internal flow of each type of rotor is clarified by the numerical analysis results.

• International Journal of Fluid Machinery and Systems
• /
• v.6 no.1
• /
• pp.11-17
• /
• 2013

Mini centrifugal pumps having a diameter smaller than 100mm are employed in many fields. But the design method for the mini centrifugal pump is not established because the internal flow condition for these small-sized fluid machines is not clarified and conventional theory is not suitable for small-sized pumps. Therefore, mini centrifugal pumps with simple structure were investigated by this research. Splitter blades were adopted in this research to improve the performance and the internal flow condition of mini centrifugal pump which had large blade outlet angle. The original impeller without the splitter blades and the impeller with the splitter blades were prepared for an experiment. The performance tests are conducted with these rotors in order to investigate the effect of the splitter blades on performance and internal flow condition of mini centrifugal pump. On the other hand, a three dimensional steady numerical flow analysis is conducted with the commercial code (ANSYS-CFX) to investigate the internal flow condition in detail. It is clarified from experimental results that the performance of the mini centrifugal pump is improved by the effect of the splitter blades. Blade-to-blade low velocity regions are suppressed in the case with the splitter blades and total pressure loss regions are decreased. The effects of the splitter blades on the performance and the internal flow condition are discussed in this paper.

• Journal of Korea Trade
• /
• v.23 no.4
• /
• pp.80-102
• /
• 2019

Purpose - This paper aims to articulate relationship about factors influencing FTA utilization by dividing them into company's external and internal factors and performing investigation on the relationship between FTA utilization and export performance. Design/methodology - This study verified factors influencing FTA utilization by dividing them into company's external and internal factors and performing investigation on the relationship between FTA utilization and export performance. Empirical analysis was performed by setting internal and external factors required for FTA utilization as variables. To achieve this, research model was established based on previous study, hypothesis was deduced, and statistical program were used to test the hypothesis. This study performed empirical analysis using statistical program of SPSS 18.0 and AMOS 18.0 for the research model. Findings - Empirical analysis was performed regarding the effect of the FTA utilization on export performance and previous study defined export performance as the company's increased economy benefits through export and increase in new transactions. Analysis was also performed for factors affecting the FTA utilization by the company and through management and response of external factors and internal factors it was confirmed that the FTA utilization by the company led to increase in the company's export performance as a result. This study proposes a method to achieve export performance based on this. Originality/value - Companies seeking to utilize the FTA sign the Contract for the International Sale of goods and there are many conditions to meet in order to receive trade preferences during the transaction process. Existing trade order and order in the FTA have to be followed. Country of origin can be seen as key in the FTA. The Rule of Origin becomes the most important evaluation standard in applying preferential tariff in the FTA. Such regulations can be seen as external factors which cannot be controlled by the company. Internal factors are capabilities owned before that can be controlled by the company. The study sought to test the variables regarding factors centered on such capability. This study verified factors influencing FTA utilization by dividing them into company's external and internal factors and performing investigation on the relationship between FTA utilization and export performance.

• Journal of Digital Convergence
• /
• v.20 no.2
• /
• pp.479-486
• /
• 2022

This study tried to identify hospital internal marketing, organizational communication, and the degree of organizational performance targeted at nurses working in university hospitals, and apprehend factors affecting organizational performance. A structured questionnaire, where 239 nurses answered, was used to figure out general features, hospital internal marketing, organizational communication, and organizational performance. Descriptive statistics, Indepented t-test, one-way ANOVA, correlation, and multiple regression analyses were used to analyze the data. The analyzing tool was IBM SPSS 21.0 program. The result of this study was as follows: hospital internal marketing 3.13±0.58 points, organizational communication 3.23±0.48 points, and organizational performance 3.34±0.51 points. Organizational performance showed a positive correlation with hospital internal marketing and organizational communication, and those two explained 61.0% of organizational performance. Therefore, hospital internal marketing strategy - encouraging nurses in individual aspect - and integrated strategy - establishing various communication channels in organizational aspect - are required to increase the organizational performance of nurses.

• Knowledge Management Research
• /
• v.16 no.1
• /
• pp.171-191
• /
• 2015

This paper investigates how internal knowledge dependency and its interaction with external knowledge adoption affect innovation performance in Korean companies. We categorize innovation performance into exploratory innovation and exploitative innovation. Especially, we examine business group effects as group headquarters and sister subsidiaries holistically form the boundary of the firm. Our empirical results first suggest that the degree of internal knowledge dependency is positively associated with exploitative innovation, but negatively with exploratory innovation. Second, internal knowledge dependency is more negatively related to exploratory innovation in independent firms than in business group affiliates. Third, independent firms' adoption of external knowledge tends to strengthen the positive relationship between internal knowledge dependency and exploitative innovation. Finally, exploitative external knowledge search appears to strengthen the negative relationship between internal knowledge dependency and exploratory innovation in both types of firms.

• Computers and Concrete
• /
• v.33 no.3
• /
• pp.309-324
• /
• 2024

Internal curing, a widely used method for mitigating early-age shrinkage in concrete, also offers notable advantages for concrete durability. This paper explores the potential of internal curing by partial replacement of sand with fine lightweight aggregate for enhancing the behavior of high-performance concrete at elevated temperatures. Such a technique may prove economical and safe for the construction of skyscrapers, where explosive spalling of high-performance concrete in fire is a potential hazard. To reach this aim, the physico-mechanical features of internally cured high-strength concrete specimens, including mass loss, compressive strength, strain at peak stress, modulus of elasticity, stress-strain curve, toughness, and flexural strength, were investigated under different temperature exposures; and to predict some of these mechanical properties, a number of equations were proposed. Based on the experimental results, an advanced stress-strain model was proposed for internally cured high-performance concrete at different temperature levels, the results of which agreed well with the test data. It was observed that the replacement of 10% of sand with pre-wetted fine lightweight expanded clay aggregate (LECA) not only did not reduce the compressive strength at ambient temperature, but also prevented explosive spalling and could retain 20% of its ambient compressive strength after heating up to 800℃. It was then concluded that internal curing is an excellent method to enhance the performance of high-strength concrete at elevated temperatures.

• East Asian Economic Review
• /
• v.21 no.2
• /
• pp.103-121
• /
• 2017

This paper experimentally studies the performance of negotiation considering individual and party, like a country, share of benefit over the best ones. It experiments two-stage bargaining games, internal and external negotiations. From the experimental results, this paper shows strong tendency to select fair allocation in the internal negotiations, but the tendency would be weaker with attractive outside option. In addition, the outside option may claim difference in individual benefit. From the regressions on individual performance in the negotiations, being a proposing party would matter to enhance the performance. However, relative individual performance within party fairness matters. Still attractive no-agreement options happen to break the tendency. As policy implication for trade negotiation, this paper warns that possible loss in individual benefit from not active participation to the external negotiations, no active role of proposer in case that players stick to internal allocations, and deviation of advantageous sector due to attractive outside options.

• Journal of Korea Trade
• /
• v.27 no.3
• /
• pp.199-216
• /
• 2023

Purpose - This study aims to identify the internal capabilities that export companies need to possess in order to utilize FTAs and to propose ways to expand their export performance through them. To achieve this goal, the study analyzed the internal factors that affect FTA utilization from a resource-based perspective, such as Origin Management Competency, Information Acquisition Competency, contract Management Competency, and Commitment to Export, based on prior research on corporate capabilities in the field of management and FTA-related research. The study ultimately aims to confirm whether a company's FTA utilization contributes to its export performance through the management and response to its internal factors for FTA utilization. Design/methodology - To achieve the research objective, this study conducted a literature review related to FTA utilization and identified the internal factors of companies that affect FTA by classifying them into Origin Management Competency, Information Acquisition Competency, contract Management Competency, and Commitment to Export Based on this, a final research model was developed, hypotheses were set through a preliminary study survey, and conclusions were drawn by analyzing the data of 312 companies. Findings - The empirical analysis results indicate that Origin Management Competency and Contract Management Competency have a positive impact on FTA utilization, while Information Acquisition Competency and Commitment to Export do not have a statistically significant impact on FTA utilization. Based on these findings, this study suggests measures for efficient FTA utilization for companies that want to utilize FTAs. Additionally, FTA utilization has a positive impact on export performance. In other words, the extent to which companies utilize the signed agreements has a positive impact on their performance. Based on these results, this study identifies the characteristics of companies that want to utilize FTAs and proposes measures for future efficient FTA utilization. Originality/value - This study has confirmed that in order for companies to utilize FTAs, they must meet the requirements of the FTA. To this end, the study has concluded that it is important to manage and address internal factors such as Origin Management Competency, Information Acquisition Competency, contract Management Competency, and Commitment to Export to increase FTA utilization. Based on these results, it can be confirmed that it is essential for companies to have an understanding and management of the internal factors that satisfy the requirements of the FTA in order to utilize the FTA.

• Journal of Korean Institute of Industrial Engineers
• /
• v.22 no.2
• /
• pp.277-302
• /
• 1996

The overall performance of BISDN depends significantly on the interconnection network or the switch fabric. Hence, it is extremely important to evaluate the performance of the network or the fabric. The well developed performance models also provide insight into the factors that determine design tradeoffs as well as quantitative estimates of their importance. The objective of this paper is to investigate and critically compare all the developed performance analysis models of FPS according to internal switch fabric structure, traffic assumptions, performance measures, methodologies, etc. FPSs are described according to their internal fabric structure. Brief history of FPS performance analysis is mentioned and performance analysis modeling is discussed.

• Korea Journal of Hospital Management
• /
• v.17 no.3
• /
• pp.83-98
• /
• 2012

The purpose of this study is to investigate IPA(Importance Performance Analysis) of the hospital choice factor between internal and external customers at S general hospital. This study was used 5 types of choice factors such as physical, interpersonal, accessibility, connection, and image. This study was used Importance Performance Analysis which can be applied to identify the strengths and weaknesses attributes from hospital customers' viewpoint. The sample was selected 116 patients and 97 internal employees for S hospital in Seoul. Data were collected with self-reported questionnaires from April 1 to 29 in 2012 and analyzed by paired t-test, scatter plot graph. The result of the study was that the perceptional gaps between internal and external consumers were existed in physical, connection and image factors, except interpersonal, accessibility. The "Keep up the good work" quadrant was interpersonal factor, and the "Low Priority" quadrant was accessibility. The findings of this study will be applied to make hospital strategic decision making and to improve marketing service quality in administrative department of hospital.