• Title/Summary/Keyword: control period

Search Result 9,311, Processing Time 0.038 seconds

Fuzzy PID Control of Warranty Claims Time Series (보증 클레임 시계열 데이터를 위한 퍼지 PID 제어)

  • Lee, Sang-Hyun;Lee, Sang-Joon;Moon, Kyung-Il;Cho, Sung-Eui
    • Journal of Information Technology Services
    • /
    • v.8 no.4
    • /
    • pp.175-185
    • /
    • 2009
  • Objectifying claims filed during the warranty period, analyzing the current circumstances and improving on the problem in question is an activity worth doing that could reduce the likelihood of claims to occur, cut down on the costs, and enhance the corporate image of the manufacturer. Existing analyses of claims are confronted with two problems. First, you can't precisely assess the risks of claims involved by means of the value of claims per 100 products alone. Second, even in a normal state, the existing approach fails to capture the probabilistic conflicts that escape the upper control limit of claims, thus leading to wrong control activities. To solve the first problem, this paper proposed that a time series detection concept where the claim rate is monitored based on the date when problems are processed and a hazard function for expression of the claim rate be utilized. For the second problem, this paper designed a model whereby to define a normal state by making use of PID (Proportion, Integral, Differential) and infer by way of a fuzzy concept. This paper confirmed the validity and applicability of the proposed approach by applying methods suggested in the actual past data of warranty claims of a large-scaled automotive firm, unlike hypothetical simulation data, in order to apply them directly in industrial job sites, as well as making theoretical suggestions for analysis of claims.

Quality Control of Radiopharmaceutical (진단용 방사성 의약품의 정도관리)

  • An, Sung-Min;Hong, Tae-Kee;Ham, Jun-Cheol;Kim, Sung-Chul
    • The Journal of the Korea Contents Association
    • /
    • v.9 no.11
    • /
    • pp.240-246
    • /
    • 2009
  • Quality control test in this field of study were carried out in 3 categories, radionuclidic purity, chemical purity and radiochemical purity. Also, indication efficiency was tested every 3 hours changed after binding the radiopharmaceutical to see how long the medicine is available for usage after indicating. The result showed that currently used radiopharmaceutical have good radionuclidic purity and chemical purity. However, radiochemical purity indication showed small differences depending on indication method and indication period. Radiopharmaceutical are indicated by treatment providers, so they need to pay more attention to the indication process and quality control to provide more efficient treatment.

The Effect of Ginseng on the Physical Performance and Lactic Acid Production in Mice (인삼(人蔘)이 흰 생쥐의 운동능력(運動能力) 및 유산생성량(乳酸生成量)에 미치는 영향(影響))

  • Hong, Sung-Il;Park, Hae-Kun
    • The Korean Journal of Physiology
    • /
    • v.9 no.1
    • /
    • pp.77-82
    • /
    • 1975
  • This experiment was carried out to observe a biological effect of ginseng on the weight gain, physical performance and lactic acid production after exercise in mice. A group of mice weighing about 19 gm was divided into ginseng and cotrol group. on the treadmill (Exp. I & II) and LDH activity of liver and heart homogenates (Exp. II) were determined. Results are summerized as follows; 1. Body weight gain was greater id ginseng group than in control and the difference was statistically significant at 9th and 16th days of experimental period. 2. Maximal running time of ginseng was found to be longer than that of control (p<0.05) in experiment I and the experiment II also revealed the significant increase in maximal running time in ginseng group. 3. Bloo lactate concentration of 48 hour-rest from physical exertion was lower in ginseng group than in control (p<0.05). 4. LDH activity in liver homogenate was lower compared to control group, but in heart homogenate, it was greater in ginseng group. Above findings may be concluded tat the range of biological dose (20 mg/mice/day) of ginseng powder stimulated the body weight gain and increase of physical performance and its mechanism might be attributable to a lower level of blood lactic acid. The adaptive change of LDH activity also contributed to the change in lactate level in blood and tissue.

  • PDF

Current Control Method for Torque Ripple Reduction in Brushless DC Motor (브러시리스 직류 전동기의 토크 맥동 저감을 위한 전류 제어 방식)

  • 이광운;홍희정;박정배;여형기;이인호;유지윤
    • The Transactions of the Korean Institute of Power Electronics
    • /
    • v.3 no.3
    • /
    • pp.191-198
    • /
    • 1998
  • This paper presents a new current control method to reduce the torque ripple due to phase commutation, when the unipolar PWM method is applied for the phase current control of brushless DC motor. Phase commutation bring about an instantaneous change in the average voltage of conducting phase so that current undulates, and this undulating current generates torque ripple. In this paper, we analyze average voltage variations of conducting phase in commutation period with PWM pattern and design current controller to compensate average variations. In addition, we prove the validity of proposed method by experimental results.

  • PDF

Voltage Control of Synchronous Generator for Ship Using a PMG Type Digital AVR (PMG Type 디지털 AVR을 이용한 선박용 동기발전기 출력전압제어)

  • Yu, Dong-Hwan;Park, Sang-Hoon;Yu, Jae-Sung;Lee, Sang-Suk;Kim, Young-Real;Won, Chung-Yuen
    • Proceedings of the KIPE Conference
    • /
    • 2008.06a
    • /
    • pp.136-138
    • /
    • 2008
  • The output voltage of synchronous generator is regulated constantly by field current control in excitation system. Most of ship generator exciter system uses the thyristor phase controlled rectifier. However this rectifier is difficult to realize that the speed control system because its control period is slower than MOSFET and IGBT type converter. Therefore, this paper deals with PMG(Permanent Magnet Generator) type digital excitation system using MOSFET for ship synchronous generator. The organization of this excitation system is very simple. When the generator is under the short circuit accident, the output voltage becomes zero state and AVR can not operate. Thus generator requires the function for flowing output current through CBS. The performance of the proposed system is evaluated on a 10kVA experimental prototype circuit in place of real ship generator.

  • PDF

The Effects of Children's Metastrategic Activities on Strategies to Control Variables at a Scientific Reasoning Task

  • Jang, Myoung-Duk;Yang, Il-Ho;Jeong, Jin-Woo
    • Journal of the Korean earth science society
    • /
    • v.23 no.2
    • /
    • pp.154-165
    • /
    • 2002
  • The purpose of this study was to examine the effects of metastrategic exercise on a scientific reasoning strategy to control variables, and investigate the developmental patterns in the strategy usage within a given period. Two groups composed of 90 fifth grade students engaged in a scientific reasoning task over six daily sessions. Additionally, one group engaged in metastrategic exercise on fictional students' strategies of controlling variables on the task, while the other spent equivalent time on an unrelated task. Based upon results of the study, the following conclusions can be drawn. First, the metacognitive exercise on the strategy to control variables has positive and long-standing effects on the strategy performance at the reasoning task. The exercise also takes effect of near-transfer. Taking into consideration only about sixty minutes of metastrategic practice, the results provide the validity of the activity in order to develop children's reasoning strategies. Second, in a scientific reasoning task, each child seems to go through one out of two developmental patterns in their usage of reasoning strategies: gradual change or fundamental change. Considering the ratio of pattern of fundamental change between the two groups, it is clear that the metacognitive exercise influences the developmental pattern of strategy usage.

Preventive effects of water extracts from Artemisiae Iwayomogi Herba on hyperlipiderma and liver damage induced by alcohol (한인진(韓茵蔯)이 알콜 투여로 유발된 흰쥐의 고지혈증과 간 손상의 예방에 미치는 영향)

  • Seo, Bu-Il
    • The Korea Journal of Herbology
    • /
    • v.22 no.1
    • /
    • pp.103-110
    • /
    • 2007
  • Objectives : This study was performed to prove the preventive effect of water extracts from Artemisiae Iwayomogi Herba on hyperlipiderma and liver damage induced alcohol. Methods : Except for the normal group, we fed rat on 25% alcohol for 55 days. And Artemisiae Iwayomogi Herba extract was administrated for the same period. We measured the serum component in rat's blood. body weight and weight of liver. Result : At first, we observed preventive effects of Artemisiae Iwayomogi Herba on hyperlipiderma induced by alcohol. Artemisiae Iwayomogi Herba group showed significant decrease of total cholesterol and triglyceride in comparison with those of the control group. Artemisiae Iwayomogi Herba group showed significant increase of body weight in comparison with those of the control group in 4weeks and 8weeks. At second, we observed preventive effects of Artemisiae Iwayomogi Herba on liver damage induced by alcohol. Artemisiae Iwayomogi Herba group showed significant decrease of GOT, ALP and LDH in comparison with those of the control group. Artemisiae Iwayomogi Herba group showed significant increase of liver weight in comparison with those of the control group. Conclusion : Reviewing these experimental results, it appears that water extracts from Artemisiae Iwayomogi Herba have pharmaceutical preventive efficacy on hyperlipiderma and liver damage induced by alcohol. Therefore further additional study should be conducted to elucidate in depth the pharmaceutical efficacy of Artemisiae Iwayomogi Herba.

  • PDF

Effect of Case Management Intervention Program for Registered Clients with Home Health Care of Hypertension (고혈압 대상자의 방문간호 중재프로그램의 효과)

  • Oh, Suk-Hee;Kim, Yong-Soon;Park, Jee-Won;Yoo, Moon-Sook
    • Journal of Home Health Care Nursing
    • /
    • v.17 no.1
    • /
    • pp.28-35
    • /
    • 2010
  • Purpose: The study compared the hypertension care efficacy of a case management intervention program for registered clients. Methods: The nonequivalent control group pretest-posttest design involved 53 registered hypertensive patients of a customized visiting health care service in S-city(n=28 experimental group, n=25 control group). Data collection and case management intervention were carried out from April to July, 2009. The experimental group had six home visits and two phone calls, and the control group had two home visits during the 8-week period. Outcome variables for test hypotheses were changes in physiologic index (blood pressure and total cholesterol) and degree of self-management performance and confidence. Results: Repeated measure ANOVA and t-test of means revealed significant differences before and after program for systolic and diastolic blood pressure and self-management performance and confidence, but no significant difference concerning total cholesterol. Conclusion: A case management program can have positive effects on blood pressure control and self management. However, research is needed to create a more effective case management for vulnerable patient populations.

  • PDF

Analysis and Practical Application of Nonlinear Load Control Model for Swing of Pendulum (비선형 단진자 운동의 하중 모델 적용과 하중 제어 분석)

  • Wang, Hyun-Min;Woo, Kwang-Joon
    • Journal of the Institute of Electronics Engineers of Korea SC
    • /
    • v.47 no.3
    • /
    • pp.63-70
    • /
    • 2010
  • We are able to find many materials of pendulum dynamic/analysis using linearized model. Usually, analysis of pendulum is to calculate for velocity, period and angle by linearized model on Newton's law. In this paper, analyzed periodical movement of pendulum using nonlinear load model. That is, analyzed load value according to location of moving pendulum at real time. And for the shake of maneuver for pendulum's location, found load control value and compared result of linearized mode with nonlinear model. The result makes know that it is possibility of nonlinear load control model to apply to various model of movement object including flight object, pendulum and etc.

Speed Sensorless Control of Switched Reluctance Motor (스위치드 리럭턴스 전동기의 센서리스 속도제어)

  • Shin, Kyoo-Jae;Kwon, Young-Ahn
    • Journal of IKEEE
    • /
    • v.2 no.2 s.3
    • /
    • pp.166-172
    • /
    • 1998
  • Switched reluctance motor(SRM) has the advantages of simple structure, low rotor inertia and high efficiency. However, position sensor is essential in SRM in order to synchronize the phase excitation to the rotor Position. The Position sensors increase the cost of drive system and tend to reduce system reliability. This paper investigates the speed control of sensorless SRM in which the Phase current and change rate are utilized in position decision, and the period of dwell angle is variable for speed control. The proposed system consists of Position decision circuit, speed controller, digital logic commutator, switching angle controller and inverter The performances in the proposed system are verified through the experiment.

  • PDF