• Proceedings of the KIEE Conference
• /
• 1992.07b
• /
• pp.1179-1181
• /
• 1992

A discrete Pl controller is implemented easily using a micro-processor, and it can be confirmed to a adaption of a system and real time processing. In this paper, a speed controller by discrete Pl control using a IBM PC/AT(12MHz) as a micro-processor is implemented and applied to a DC servo motor. In designing the discrite Pl controller, a sampling time and a speed is accepted from key-board, and is processed the control coefficient automatically, and than calculate the gain. Therefore the speed of a DC servo motor is obtained and controlled regulaly. The designed and manufactured discrete Pl control system is experimented. The result shows the good response at the 60 RPM to 250 RPM on the load using the load-spring. The speed error is under 1% on the steady load, but nearly 2-3% on the transient load.

• The Journal of Economics, Marketing and Management
• /
• v.7 no.4
• /
• pp.1-5
• /
• 2019

Purpose - Along with the rapid growth of the economics and IT industry, E-commerce appears as the next potential area of world economics. For this no-entity shops commerce style, logistics is crucial for the success of E-commerce. Research design, data and methodology - In this paper, Dangdang.com, the largest online marketplace in China, is studied and a conceptual model is present, to develop a practical way to develop the logistics system in E-commerce situation. Results - This research finds that following 4 factors are critical success factors for E-commerce logistics: 1) logistics centres are very important to control the inventory management; 2) keep good cooperation with third-party logistics (3PL) can guarantee good quality shipping service and also can reduce delivery costs; 3) build strong information system; 4) quick response system also needed for an efficient logistics system. When E-commerce firms are developing their logistics systems, they should pay more attention to these 4 critical success factors. Conclusions - In summary, successful 3PL management is vital for competing regionally and globally throughout the logistics value chain. We see information system as an enabler in logistics management to get the right products to the right place in the right quantity at the right time and to provide quality services to satisfy the customer's needs.

• THE JOURNAL OF KOREAN ORIENTAL ONCOLOGY
• /
• v.8 no.1
• /
• pp.93-101
• /
• 2002

Objectives This experimental study was carried out to evaluate the effects of Phellinus Linteus on immune activation. Methods In order to investigate the effect of Phellinus Linteus, the following was performed: The fraction of $CD4^+$, $CD8^+$, $CD19^+$ in splenic cell, gene expression of IL-12 (p35), IL-12 (p40) , $IFN-{\gamma}$, and splenic cell proliferation by PL-E. Results PL-E helped $CD4^+$, $CD8^+$, $CD19^+$ expression more effectively compared with control group. PL-E helped IL-12 (p35), IL-12 (p40), $IFN-{\gamma}$ gene expression in splenic cells more effectively compared with control group. PL-E proliferated splenic cells more effectively compared with control group. Conclusions: It is suggested that PL-E is able to activate immune response system.

• Proceedings of the KIEE Conference
• /
• 1998.07b
• /
• pp.731-733
• /
• 1998

PID controllers are widely used in the process industries such as power plants and chemical plants. Several methods for determining PID controller parameters have been suggested to improve tuning results by various performance criteria during the past years. These methods may not produces satisfactory closed loop response by the characteristics of controlled processes. In this paper, using a model of gas turbine system obtained by operating data of Gunsan C/C, we examines the performance of PI controllers determined by various performance criteria and suggests which tuning methods can be optimally used in gas turbine control system of Gunsan C/C.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2022.05a
• /
• pp.594-595
• /
• 2022

In the process leading to the continuous use of mobile payment system users, emotional and cognitive reactions are carried out. In this study, a questionnaire was conducted to determine the effect of external factors(social, system, service factors) of the mobile payment system on the continuous use of emotional responses(pleasure, emotional trust) and cognitive responses(cognitive trust). The structural model was tested using SPSS and PLS. As a result of the analysis, it was found that external factors affect emotional and cognitive responses, and cognitive responses affect continuous use.

• Proceedings of the KIPE Conference
• /
• 2002.07a
• /
• pp.150-153
• /
• 2002

This paper designed a robust control of an induction motor using a disturbance cancellation observer of a feedforward control. The speed response of conventional Pl controller characteristic is affected by variations of load torque disturbance. In the proposed system the speed control characteristic using a feedforward control isn't affected by a load torque disturbance.

• Proceedings of the KIPE Conference
• /
• 2002.07a
• /
• pp.179-182
• /
• 2002

This Paper described a robust control of an induction motor using a disturbance cancellation observer of a feedforward control, The speed response of conventional Pl controller characteristic is affected by variations of load torque disturbance. Tn the proposed system, the speed control characteristic using a feedforward control isn't affected by a load torque disturbance.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.7 no.3
• /
• pp.303-312
• /
• 2002

In this paper, a fuzzy logic controller(FLC) for parallel operation system of PWM converters with high performances is proposed and a PI controller is also realized to compare with the performances of the proposed FLC. The simulation and experimental results show that performances of the proposed FLC are far more excellent compared with those of PI controller, especially in points of DC voltage transient response characteristics and current control transient response characteristics at step increase of rated load. To verify the superiorities of the proposed FLC and actually apply it in industrial field, Simulation iud experimental results are provided to verify the implemented a PWM converter system with 15kw capacity in paralleled with two 7.5kW PWM converters.

• Journal of Internet Computing and Services
• /
• v.5 no.1
• /
• pp.67-84
• /
• 2004

Real-time database systems (RTDBS) are database systems whose transactions are associated with timing constraints such as deadlines. Therefore transaction needs to be completed by a certain deadline. Besides meeting timing constraints, a RTDBS needs to observe data consistency constraints as well. That is to say, unlike a conventional database system, whose main objective is to provide fast average response time, RTDBS may be evaluated based on how often transactions miss their deadline, the average lateness or tardiness of late transactions, the cost incurred in transactions missing their deadlines. Therefore, in RTDBS, transactions should be scheduled according to their criticalness and tightness of their deadlines, even If this means sacrificing fairness and system throughput, And It always must guarantee preceding process of the transaction with the higher priority. In this paper, we propose an efficient real-time scheduling algorithm (Multi-level EFDF) that alleviates problems of the existing real-time scheduling algorithms, a real-time concurrency control algorithm(2PL-FT) for firm and soft real-time transactions. And we compare the proposed 2PL F[ with AVCC in terms of the restarting ratio and the deadline missing ratio of transactions. We show through experiments that our algorithms achieve good performance over the other existing methods proposed earlier.

• Journal of Community Nutrition
• /
• v.7 no.2
• /
• pp.79-84
• /
• 2005

A vitamin B-6 (B-6) intake higher than the current Recommended Dietary Allowance (RDA) has been found to provide an improvement in immune system. Seven premenopausal women consumed their usual diet with the exception of foods relatively high in vitamin B-6 for a total of 27 d. After 7 d, all subjects received a multivitamin supplement containing 2mg B-6 and 4 subjects were given an additional 50mg of B-6 supplement for 20 d. Lymphocyte response to phytohemagglutinin (PHA) was measured before and after the supplementation. To determine the effect of different forms of B-6 on lymphocyte proliferation, cell culture media supplemented with pyridoxal (PL) and PLP, as well as B-6 free media, were tested. A 50mg B-6 supplement significantly increased vitamin B-6 status. There was no further enhancement on lymphocyte proliferation when subjects were taking an additional 50mg of vitamin B-6 supplement. In general, lymphocyte proliferation in media with either PLP or PL did not show any prominent difference. These [m-dings suggest that there may be no further benefits of a B-6 dose beyond twice that of the current RDA on lymphocyte proliferation. Further studies are necessary to examine the effect of the B-6 intake level on activities of enzymes involved in cellular B-6 metabolism in lymphocytes to provide substantial insight into the mechanisms underlying the role of B-6 in the lymphocyte proliferation.