• Journal of Environmental Science International
• /
• v.20 no.6
• /
• pp.767-773
• /
• 2011

The objectives of this research are to investigate the proper coagulation conditions which are a type and doses of coagulants, mixing conditions (velocity gradients and mixing times), pH and so on through Jar-test, to evaluate the flux variations, permeate, backwashing according to characteristics of pretreatment of the wastewater by means of MF membranes for river maintenance water reuse. The effluent water from B-city K-sewage treatment plant are used for this research. Turbidity and suspended solids(SS) are 14.2 NTU and 10.4 mg/L respectively. This condition causes fouling for membrane process. The flux decline could be reduced when coagulation pretreatment was carried out. Optimal coagulations PAC which are commonly used in the sewage treatment plant was observed in this research. The results indicate that an optimal coagulation dose and pH are 80 ppm and pH of 7 respectively, but coagulation efficiency was lower at strong acid or strong base. Results showed that continuous and steady operations in membrane separation process by means of the effective removal of organic matter and turbidity with coagulation pretreatment of sewage secondary effluent were achieved.

• Journal of the Korean Society of Industry Convergence
• /
• v.13 no.1
• /
• pp.49-54
• /
• 2010

Lean 6 sigma has recently been used to describe a management system which combines lean management and 6 sigma. The marriage between Lean manufacturing and 6 sigma has proven to be a powerful tool for cutting waste and improving the organization operations. Time and quality are the most important metrics in improving any company's production and profit performance. lean 6 sigma is a management innovation for improving production efficiency, process quality, cost reduction, investment efficiency and customer's satisfaction. in this paper, Advanced cell line is builded the home appliance goods of the LCD TV final assembly line of domestic company line, training the multi-skilled man and controlling the production information system based on Lean 6 sigma.

• The Journal of Economics, Marketing and Management
• /
• v.11 no.6
• /
• pp.43-55
• /
• 2023

Purpose: The purpose of this study was to identify the relationship between smart factory utilization and continued use intention between UTAUT, dynamic capabilities of smart factory construction companies and present the company's strategic direction. Research design, data, and methodology: In this study, a structured research model was derived to confirm the relationship between UTAUT, dynamic capabilities, smart factory utilization and continued use intention and the difference according to Technology perception. For analysis a total of 223 valid questionnaires from e-commerce users were used. Confirmatory factor analysis, correlation analysis, and structural equations were conducted to verify. Results: Both UTAUT, dynamic capabilities had a significant effect on smart factory utilization as well as continued use intention. It was found that the relationship between UTAUT, dynamic capabilities, smart factory utilization, and continued use intention. differed depending on the technology perception. Conclusions: Organizational members utilize the smart factory in anticipation of effects such as work performance and various improvements. Smart factory data will be used continuously when it is useful for business processes and operations. It is necessary to establish strategies and provide training to improve the technical level and capabilities of organizational members. Through this, a strategy is needed that can be continuously used by utilizing the information obtained through smart factory to improve work efficiency, productivity and efficiency increase is needed

• Proceedings of the KIEE Conference
• /
• 2009.04a
• /
• pp.195-197
• /
• 2009

It is a proven fact with the opening of the Seoul metro line number 1 in 1974 traffic congestion on the roads has decreased and the efficiency of people transportation in general has greatly been enhanced in the downtown and surrounding areas of Seoul. Even today construction of new subway lines are under way and many more are being planned due to the easy access to stations, short waiting and average travel times, compared with personal vehicles, contributing to the efficiency of the public transportation systems that are linking the downtown areas and also the intercity systems in moving passengers during rush hour and times of special event. Since the labour costs of the train operator in any large city based subway system accounts for a major part of the operating costs per kilometer and to ensure cost efficient operations, especially during non-peak hours, it is necessary to implement an unmanned(auto-driven) subway system. In order to implement such a system it is imperative that the on-board and wayside signalling control systems be fully automated as well. Only through proper examination of safety procedures not only by the AUGT(Automated Urban Guided Transport)system but also by ail the international standards organizations involved can safely and stability be ensured.

• The Transactions of the Korean Institute of Electrical Engineers P
• /
• v.63 no.2
• /
• pp.95-101
• /
• 2014

In this paper, UPS, with a built-in instantaneous sag drop compensation features, was developed to improve performance. The improved UPS, using instantaneous moving average method, compensates by quickly measuring the voltage and series inverter of half-bridge type, using line-interactive method that links with the voltage of the battery and power source, was developed. In addition, by developing a parallel inverter that uses a high-efficiency PWM switching method, overall UPS system was enhanced. To verify the performance of the proposed algorithm, single-phase 5[kVA] UPS systems were designed and the experimental system was constructed. The low-cost type of Cortex-M3 module CPU STM32F103R8T6 (32[bit]) is attached and the switching time of mode transfer was set within 4 [ms]. THD of the linear load operates in less than 3[%], and the stability of the output voltage operates in approximately ${\pm}2[%]$ range. The superior performance of the operations was confirmed with the system set as above.

• Journal of Biosystems Engineering
• /
• v.19 no.4
• /
• pp.291-300
• /
• 1994

It is desired to operate tractor engines at or near maximum torque much of the time in field operation to increase fuel efficiency. To do this it is necessary to reduce engine speed and to shift gears to higher ratios as frequently as possible. Because of load variations in most drawbar work and inconvenience in gear shift, however, gear-type transmission are usually set in one ratio at unnecessarily high engine speeds, and engine-torque variations are used to compensate for changes in drawbar load. As a result, the most of time the tractor is not operated efficiently in terms of fuel consumption and work output. The objective of this study was to develop an automatic control system which is able to operate a tractor equipped with gear transmission under the optimal condition in terms of fuel efficiency with automatic governor setting and gear shift. An indoor experimental test set which can be used to simulate tractor operation, control engine speed and transmission ratio was developed in the previous paper. In this paper, the performance of the optimal operation system is reported. Through a series of tests, it was found that the automatic control system for optimal operation of tractors with gear transmission had a satisfactory performance.

• Journal of the Korea Society of Computer and Information
• /
• v.10 no.3 s.35
• /
• pp.267-273
• /
• 2005

The internet is not simply a new technology that businesses are adopting to reduce their costs of operations and increase revenues. It is literally transforming the way business work. Electronic commerce refers generally to all forms of transactions relating to commercial activities. This research was conducted to identify the critical success factors of electronic commerce. In this study it is found that price and customer service are very important to increase customer satisfaction and intention to repurchase. In addition, the result of this study shows that (1) ease of use, (2) transaction efficiency and (3) qualify assurance are very important to increase customer satisfaction. And, the result of this study shows that (1) ease of use and (2) security are very important to increase intention to repurchase.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.63 no.12
• /
• pp.1627-1636
• /
• 2014

In real-time electricity price environment, the energy management system can provide the significant advantage to the residential, commercial and industrial customers since it can reduce the electricity charge by controlling the load operation effectively in response to time-varying price. However, the earlier studies for load management mainly focus on the residential and commercial customers except for the industrial customers because most of load operations in industrial sector are intimately related with production schedule. So, it is possible that the inappropriate control of loads in industrial sector causes huge economic loss. In this paper, therefore, we propose load control algorithm for factory energy management system(F-EMS) to achieve not only minimizing the electricity charges but also maintaining production efficiency by considering characteristics of load operation and production schedule. Considering characteristics of load operation and production schedule, the proposed load control algorithm can reflect the various characteristics of specific industrial customer and control their loads within the range that the production efficiency is maintained. Simulation results show that the proposed load control algorithm for F-EMS leads to significant reduction in the electricity charges and peak power in industrial sector.

• International Journal of Knowledge Content Development & Technology
• /
• v.11 no.4
• /
• pp.87-99
• /
• 2021

The study examines the relationship between co-operative society governance and members' satisfaction. Co-operative societies face problems of how to keep balance between efficiency and governance because those in charge of operations of co-operative; the board and the staff must meet two demands i.e. good business practice and the social responsibility which involves the satisfaction of members. The objective of this study is to examine the relationship between co-operative governance and members' satisfaction using Ambrose Alli University Workers/Farmers Multi -Purpose the Co-operative Society as a case study. The data collected in this study were obtained through structured questionnaire. Data analyzed were subjected to descriptive statistics and graphs. The data analyzed indicated that the challenges facing the co-operative society include theft /fraud and mismanagement. Members agitated for transformation of the co-operative society to operate in line with the guidelines of the Central Bank of Nigeria. It was recommended that for efficiency and high productivity, staff should be trained. Also there is need for innovative technology and the necessity for the cooperative society in question to network with other organizations.

• Journal of Korean Academy of Nursing Administration
• /
• v.16 no.3
• /
• pp.295-305
• /
• 2010

Purpose: This study was conducted to evaluate the economic efficiency of a community-based nursing care center to help policy makers determine whether or not to invest in similar facilities. Methods: The subjects were 101 elderly people over 65 years who participated in a health management program from February 1 to July 31, 2007. Direct cost was estimated with center operations cost, medical cost for out-patients and pharmacy cost. Indirect cost was measured by transportation cost. Direct benefit was calculated by saved medical cost for out-patients, saved pharmacy cost, saved transportation cost, and reducing hospital charges. Indirect benefit was estimated with prevention of severe complications. Economic efficiency was evaluated by cost-benefit ratio and net benefit. Results: Operating a community-based nursing care center was found to be cost-effective. Specifically, the cost of operating the center evaluated here was estimated at 135 million won while the benefit was estimated at 187 million won. Benefit-cost ratio was 1.38. Conclusion: The Community-based nursing care center that was described here could be a useful health care delivery system for reducing medical expenditures.