• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1993.06a
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• pp.1054-1057
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• 1993

A direct method of fuzzy inference and a fuzzy algorithm with learning function are applied to the steam generator level control of nuclear power plant. The fuzzy controller by use of direct inference can control the steam generator in the entire range of power level. There is a little long response time of fuzzy direct inference controller at low power level. The rule base of fuzzy controller with learning function is divided into two parts. One part of the rule base is provided to level control of steam generator at low power level (0%∼30% of full power). Response time of steam generator level control at low power level with this rule base is shown generator level control at low power level with this rule base is shown to be shorter than that of fuzzy controller with direct inference.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.601-604
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• 1996

It is well known that steam generator water level control at low power operation has many difficulties in a PWR (pressurized water reactor) nuclear power plant. The reverse process responses known as shrink and swell effects make it difficult to control the steam generator water level at low power. A new automatic control logic to remove the reverse process responses is proposed in this paper. It is implemented in PLC (programmable logic controller) and evaluated by using test equipment in Korea Atomic Energy Research Institute. The simulation test shows that the performance requirements is met at low power (below 15%). The water level control by new control logic is stabilized within 1% fluctuation from setpoint, while the water level by YGN 3 and 4 control logic is unstable with the periodic fluctuation of 25% magnitude at 5% power.

• International journal of advanced smart convergence
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• v.12 no.4
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• pp.370-377
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• 2023

Previous research has demonstrated that happy moods are known to promote feeling-based processing, whereas sad moods promote reason-based processing. The current research investigates a boundary condition for the effects of a happy mood on feeling-based decision making. This research proposes that the level of control (low vs. high) one exercises in a happy situation can promote a greater reliance on feelings (vs. reasons) in making judgments and decisions. Specifically, we hypothesize that (1) a happy individual in a situation where control level is low (vs. high) will be more likely to choose a cognitively (vs. affectively) superior option (hypothesis 1), and (2) a happy individual in a situation where control level is low (vs. high) will exert reason- (vs. feeling-) based processing (hypothesis 2). Consistent with the hypothesis 1, the results of two experiments show that happy individuals are more likely to choose cognitively versus affectively superior options in a situation where control level is low (vs. high). Moreover, the mediation analysis confirms that happy individuals are more likely to rely on cognitive, reason-based decision making when their control level is low, which supports the hypothesis 2.

• Journal of Electrical Engineering and Technology
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• v.10 no.1
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• pp.280-287
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• 2015

Three-level PWM rectifiers applied in medium voltage applications usually operate at low switching frequency to keep the dynamic losses under permitted level. However, low switching frequency brings a heavy cross-coupling between the current components $i_d$ and $i_q$ with a poor dynamic system performance and a harmonic distortion in the grid-connecting current. To overcome these problems, a mathematical model based on complex variables of the three-level voltage source PWM rectifier is firstly established, and the reasons of above issues resulted from low switching frequency have been analyzed using modern control theory. Then, a novel control strategy suitable for the current decoupling control based on the complex variables for $i_d$ and $i_q$ is designed here. The comparisons between this kind of control strategy and the normal PI method have been carried out. MATLAB and experimental results are given in detail.

• Journal of Mechanical Science and Technology
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• v.14 no.6
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• pp.645-654
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• 2000

In this paper, low level control algorithms of a metal belt CVT are suggested. A feedforward PID control algorithm is adopted for line pressure based on a steady state relationship between the input duty and the line pressure. Experimental results show that feedforward PID control of the line pressure guarantees a fast response while reducing the pressure undershoot which may result in belt slip. For ratio control, a fuzzy logic is suggested by considering the CVT shift dynamics and on-off characteristics of the ratio control valve. It is found from experimental results that a desired speed ratio can be achieved at steady state in spite of the fluctuating primary pressure. It is expected that the low level control algorithms for the line pressure and speed ratio suggested in this study can be implemented in a prototype CVT.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1039-1043
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• 2005

Despite the many significant advances made in robot architecture, the basic approaches are deliberative and reactive methods. They are quite different in recognizing outer environment and inner operating mechanism. For this reason, they have almost opposite characteristics. Later, researchers integrate these two approaches into hybrid architecture. In such architecture, Reactive module also called low-level motion control module have advantage in real-time reacting and sensing outer environment; Deliberative module also called high-level task planning module is good at planning task using world knowledge, reasoning and intelligent computing. This paper presents a framework of the integrated planning and control for mobile robot navigation. Unlike the existing hybrid architecture, it learns topological map from the world map by using MST (Minimum Spanning Tree)-based SOFM (Self-Organizing Feature Map) algorithm. High-level planning module plans simple tasks to low-level control module and low-level control module feedbacks the environment information to high-level planning module. This method allows for a tight integration between high-level and low-level modules, which provide real-time performance and strong adaptability and reactivity to outer environment and its unforeseen changes. This proposed framework is verified by simulation.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.301-304
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• 1997

Two options arising during implementation of an advanced model-based control system on a process with low-level loops are discussed. Strengths and deficiencies of the options are examined and methods to overcome the deficiencies are proposed. Simulation results of a CSTR and distillation column are presented to demonstrate the performance improvements.

• Journal of Plant Biology
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• v.12 no.3
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• pp.15-25
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• 1969

To investigate the radiation effect of P-32 on the soybean plants, the seeds treated with various levels of P-32 solution were sown and cultured in the pots. The growth of the plants and the contents of the macroelements were observed and the following results were obtained. 1) The linear growth of the plants at the early stage seemed to have been promoted by the low-level P-32 treatemnt. At the later growing stage, however, this difference among treatments were less conspicuous. 2) The plants of high level P-32 application showed some growth damaging symptom at the early growing stage. Later this damage was recorded as the time went on and these plants showed even better growth than the control. As a result at the late growing stage, they ensued highest growth. 3) The plants showed in general more growth at the low activity level than at the high-level at the early growing stage. At the late stage, however, the high-level activity promoted more growth than the low-level. 4) At the early growing stage P-32 treatment produced in general significantly more lower than control. At the later stage, however, this difference was not clearly seen. 5) The P-32 treatment seemed to have stimulated earlier florescence and this tendency was more clearly observable eapecially at the high activity level. 6) The weight of the air-dried seeds tended to be increased through P-32 treatment by 10-45%. This tendency was clearly observed especially at the low-level activity. 7) As for the contents of the various macroelements in the leaves, the nitrogen showed significantly larger contents at the middle level(S1) P-32 treatments. The phosphorous contents showed also highest at the middle levels activity and lower both at the high and low-activity levels. The potassium contents was proved, on the contrary, higher at the low-level activity and lower at the high-level. 8) The nitrogen contents in the stems was found significantly higher than control, except at the low-activity level. The phosphorous showed higher contents at the low-activity level and no significant difference at the high-activity level. As for the contents of potassium, calcium and magnesium, three seemed no significant difference among treatments. However, the magnesium showed somewhat higher content at the low-activity level, whereas the calcium was proved high than control. 9) The inorganic contents in the root showed that N and P in the P-32 treated plant were significantly higher than the control and the K-contents was, on the contrary, significantly higher at the control than the rest of the treatments. As for the calcium and magnesium there showed no difference among all treatments.

• Journal of Korea Game Society
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• v.13 no.2
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• pp.131-142
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• 2013

The current study examined how different level of self-constol and construal level influences game users' game addiction. Also we explored the interaction effect between the individual's self-control and construal level on game addiction. To answer the research questions, we conducted an online survey and total 918 participants were selected for the final analysis. According to the results, users with low level of self-control and low-level construal showed higher level of game addiction. In addition, we found a significant interaction effect between self-control and construal-level on game addiction. In high self-control group, game addiction level was low regardless of level of self-construal. However, in low self-control group, the level of construal-level affected game addiction. We found that construal-level played an important mediating variable. These findings suggest a noble insight for autonomous control in alleviatinggame addiction by changing one's level of self-control and self-construal.

• Journal of Families and Better Life
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• v.27 no.5
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• pp.123-135
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• 2009

The purpose of this study was to investigate the effects of family conflict and self-control on school maladjustments of early adolescents. Subjects of this study consisted 662 middle school students drawn from 4 middle schools in Cheong-ju city. The results of this study were as follows: First, younger students' maladjustment to teachers was influenced by variables such as school year, economic levels, conflict strength between parents, conflict settlement between parents, reliability between parents and children, communication between parents and children and self-control, etc. In other words, students' maladjustment to teachers was high at the students in the 2nd year rather than in the 1st year, low economic level, high conflict strength between parents that younger students perceived, low conflict settlement between parents, low reliability between parents and children, high hostility between parents and children and low self-control. Second, younger students' maladjustment to the class was influenced by variables such as gender, school year, economic levels, conflict strength between parents, reliability between parents and children, communication between parents and children, and self-control, etc. In other words, young students' maladjustment to the class was high at the 2nd year students rather than at the 1st year students, low economic level, high conflict strength between parents, low reliability between parents and children, poor communication between parents and children, and low self-control. Third, younger students' maladjustment to rules was influenced by variables such as school year, economic level, conflict level between parents, hostility between parents and children, and self-control, etc. In other words, younger students' maladjustment to rules was high at the 1st year students rather than the 2nd year students of middle school, low economic level, high conflict strength between parents, high hospitality between parents and children and low self-control, etc. Fourth, younger students' maladjustment to friends was influenced by variables such as conflict strength between parents, conflict settlement between parents, hospitality between parents and children, and self-control, etc. In other words, younger students' maladjustment to friends was high at high conflict strength between parents, low conflict settlement between parents, high hospitality between parents and children and low self-control, etc. In the study, self-control was found to be the most important variable at younger students' maladjustment to teachers, class and rules, etc, and conflict settlement between parents was found to be the most significant variable at younger students' maladjustment to friends.