Earticle

본 연구에서는 자동제어시스템이 리액터 운전에 미치는 영향을 분석해 보았다. Propylene 리액터 공정은 복잡하게 구성되어 일반적으로 효율이 낮고, 생산성이 떨어지는 문제로 인해 경제적 손실이 많다. 본 연구에서는 장애요인을 보완하여 운전효율을 높이고, 생산성을 향상시키는 목적으로 연구 모델을 제시하였다. 기존 공정의 구성 을 분석하여 하드웨어 시스템 및 소프트웨어 시스템을 독창성 있는 모델로 보완하였다. 설비의 구성을 연간 60 만톤 /Year 프로플린을 생산하는 리액터 8기를 기준으로 적용하였다. 연구 모델 적용결과 운전 효율이 높아졌고, 안정성 91%과 더불어 생산량이 90∼95% 으로 증가하였다. 향후 연구는 생산성 100% 향상을 위한 연구모델을 제시할 예정 이다. 추가적으로 프로플린 부산물인 수소 생산공정인 PSA 시스템의 안정성과 생산성 향상 방안에 대해 연구하고자 한다.

In this study, we analyzed the effects of the automatic control system on the reactor operation. The Propyrene Reactor process is complex and typically is inefficient and costly due to the lack of productivity. In this study, a research model was presented with the aim of supplementing obstacles to enhance operational efficiency and increase productivity. The configuration of the existing processes was analyzed to complement the hardware and software systems with original models. The composition of the facility is applied to eight reactor units producing 600,000 ton/year propylene per year. As a result of applying the research model, efficiency of operation was increased, and production volume increased from 90 to 95%, along with 91% Reliability. Future studies will present a research model to improve productivity by 100 percent. In addition, we will study the stability and productivity improvement of PSA (Pressure Swing Adsorption) systems, which are the hydrogen production process of propylene by-products.

Grid-connected distributed power generation has been widely used in green energy generation. However, due to the distributed characteristics, distributed power generation is difficult to be dynamically allocated and monitored in the electrical control process. In order to solve this problem, this research combined the Internet of Things (IoT) with the automatic control system of electrical engineering to improve the control strategy of the power grid inverter according to the characteristics of the IoT system. In the research, a connection system of the power grid inverter and the IoT controller were designed, and the application effect was tested by simulation experiments. The results showed that the power grid inverter had strong tracking control ability for current and power control. Meanwhile, the electrical control system of the IoT could independently and dynamically control the three-phase current and power. The given value was reached within 50 ms after the step signal was input, which could protect the power grid from being affected by the current. The overall system could realize effective control, dynamic control and protective control.

The existing electrical engineering design method and the dynamic objective function in the application process of automatic control system fail to meet the unbounded condition, which affects the control tracking accuracy. In order to improve the tracking control accuracy, this paper studies the electrical engineering design method based on neural network and the application of automatic control system. This paper analyzes the structure and working mechanism of electrical engineering automation control system by an automation control model with main control objectives. Following the analysis, an optimal solution of controllability design and fault-tolerant control is figured out. The automatic control power coefficient is distributed based on an ideal control effect of system. According to the distribution results, an automatic control algorithm is based on neural network for accurate control. The experimental results show that the electrical automation control method based on neural network can significantly reduce the control following error to 3.62%, improve the accuracy of the electrical automation tracking control, thus meeting the actual production needs of electrical engineering automation control system.

Reducing aircraft speed is the important task in the Rejected Takeoff and/or landing process. It is known that the effect of the Speedbrake is most important factor during the rejected takeoff maneuver in particular near V1 on the critical field length runway. The B747 designer created Automatic Speedbrake Control System to relieve pilot workload, improves brake operation and ensures proper Speedbrake operation for rejected take off. However, those who make the Rejected Takeoff procedure ignored the Automatic function and made it does all manual operations. This lets procedures difficult, complicated, and a cause of confusion and pilot error. This study was conducted to commentary the mechanism and function of the Automatic Speedbrake Control System of B747-8 and to propose appropriate B747-8 Rejected Take off procedures for its function to reduce the workload of pilots and contribute to reduce the possibility of pilot error during Rejected Takeoff.

In the U.S., performance assessment on the Automatic Exposure Control system (AEC) is managed according to the Mammography Quality Standards Act (MQSA). However, The AEC is not available in the performance assessment conducted in Korea. Also, there is no study made on the performance of the automatic exposure control system for mammography in Korea. For this reason, this study examined the performance of the automatic exposure control system for mammography that was clinically used in the Incheon area. Result showed that the difference of the mean optical density was 0.79 ~ 2.81. This implies that some devices caused unnecessary x-ray exposure to patients. Furthermore, only 61.5% of the entire experimental device was shown to be satisfactory in terms of change in mean optical density. Moreover, in terms of the subject's thickness, change in radiographic density was shown to be severe among lower X-ray tube voltage while there was severe density change in X-ray image depending on X-ray tube voltage among the subjects with more thickness. Therefore, it is suggested to provide performance management on the AEC for mammography.

Purpose: This study investigated the effects of excretion care using a smart automatic defecation treatment system on skin humidity, pressure ulcer (PU) occurrence, and severity of Incontinence-Associated Dermatitis (IAD) among patients with incontinence residing in long-term care facilities. Methods: Each patient in the experimental group was fitted with a smart automatic defecation treatment system. The system detected the release of urine/stool via a built-in sensor, followed by suction, cleaning with a water jet, and drying with warm air. Incontinence management for the control group involved the use of wet wipes for cleaning and changing diapers. The nursing interventions lasted for 2 weeks, and data were collected at baseline, week 1, and week 2. Descriptive statistics, t-tests, and the repeated-measures analysis of variance were used for data analysis. Results: The analysis revealed statistically significant differences in skin humidity and IAD between the experimental and control groups. Conclusion: This study is pertinent because it demonstrated the positive effects of excretion care using a smart automatic defecation treatment system on skin humidity, PU risk, and IAD among patients with incontinence residing in long-term care facilities. Further research is necessary to investigate additional factors such as pressure and physiological traits.

The necessity for more accurate automatic flatness control(AFC) system has increased of customers' requirement for cold rolled steel sheet. Therefore, many cold rolling mills replaced its AFC system with a measuring roll of the contact type form the non-contact type. In this paper. The performance of AFC system of contact type has been investigated under industrial conditions. It has two kinds of actuator: roll bender, spot cooling system. The test results are as follows: The more strip thickness is thick, the smaller the I value, and the more it is thin, the bigger the I value. And a complex distribution of strip tension was controlled, for example, not only a pocket wave but also a simple center wave and edge wave. Because the tension deviation is larger at acceler- ation speed and decelerationspeed than steady speed, AFC system of contact type is better to adopt over 50m/mim. AFC system reduces rapidly large flatness deviation. The maximum I value of strip has been decreased to 13 I, and sticker, defects caused by poor flatness, have been decreased about 60%.

Recently, the necessity for more accurate automatic gauge control has increased of customers' requirement for cold rolled steel sheets with thinner gauge and better gauge quality. Therefore, many cold rolling mills replaced its electric screw down automatic gauge control system with a new hydraulic automatic gauge control system, to ensure closer gauge tolerance. In this paper, The performance of a hydraulic automatic gauge control system for cold rolling has been investigated under industrial conditions. It was investigated that variation of gauge deviation according to the final products thickness, cold rolling speed and pass number, in the actual rolling mill. As a result, it was found that the system enables strip thickness variation to be reduced substantially and caused by poor gauge deviation have been drastically decreased. The test results are as following. The more the exit steel strip thickness is thick, the smaller the aguge deviation rate is large, and the more it is thin, the large the gauge deviation rate is large. Because the gauge deviation is larger at accleration speed and deceleration speed than steady speed, so automatic gauge control system is better to adopt over 50m/min. automatic gauge control system reduces rapidly large thickness deviation.

The look up table method conventionally applied to control the inner temperature and humidity of a laver drying machine has repeatedly occurred not only laver's damage but also inferior goods since the reaching time at the optimum state takes a long time. In this paper, a fuzzy control theory instead of the look up table was proposed to reduce the reaching time at the optimum state. The proposed method used six input variables and four output variables for the fuzzy control, and a triangle rule for a fuzzifier, The Mandani's min-max method was applied to a fuzzy inference. Also, the mean method of maximum was applied to a defuzzifier. The method applied to the fuzzy controller contributed to reduce the reaching time at the optimum state, and to minimize not only laver's damage but also inferior goods.

Plasma arc cutting is one of the most widely used processes in metal cutting fields and is a process that produces parted metal plates by cutting them with an arc plasma established between the electrode tip and the plate(workpiece). When the tip-to-workpiece distance varies during cutting, the cut quality, for example the kerf width, is deteriorated by the change of plasma arc. The variations of tip-to-workpiece distance are due to the different factors such as inaccuracies in setting the torch or workpiece, thermal distortions during cutting, and uneven surface of workpiece. The control to keep the tip-to-workpiece distance constant is thus indispensable to improve the flexibility of automatic plasma arc cutting system applications. In this study, an arc sensor which utilizes the electrical signal obtained from the plasma arc itself was developed. The arc sensor has an advantage that no particular sensing device is necessary and real-time sensing of the tip-to-workpiece distance is possible directly under the plasma arc. The relationship between plasma arc voltage and tip-to-workpiece distance was determined through the repeated experimental results. The model was used for developing an automatic tip-to-workpiece distance control system of plasma arc cutting. It could be shown that the proposed system has a successful capability of tip-to-workpiece distance control.

A new design concept for integrated thermal energy storage system is suggested to increase energy saving rate for heating and cooling system of the closed glass greenhouse. Heat pump of air source is installed in the mechanical room and air flows then controlled by damper system located between the greenhouse and outdoor environments. A damper control algorithm is designed to enhance the usage of excessive energy in the glass greenhouse. Since the proposed system is installed at the actual glass greenhouse site for experimental verification of energy savings, the proposed system with damper control is compared with conventional greenhouse heating and cooling system. From results, it is found that more than 10% increase of energy saving rate is achieved.

The first aim of the study is to improve the productivity by uniformizing the thickness of coating and reducing quality-inspection time. The second aim is to cut down on the raw materials for coating by prevent the waste of spraying in the air during a painting process through a real-time coating-sizerecognition monitering to fit the target components. To achieve the two aims, a simplified version of automatic coating control system for recognition of coating for vessels and Spray. With the sytem, following effects are expected: First, quality improvement will be achieved by uniformizing the film-thickness. Second, it will reduce the waste of coating paint by constructing the speed of the coating, the spray gun robot transfer time, and the number of DBs according to the size of the vessel. Third, as a 3D industry, it will be able to solve the difficulty of supply of labors and save up the labor costs. Therefore, in the future, further research will be needed to be applied to various products with DB design that designates the variable value, which is added for each type of pieces by comparing the difference between various types of workpieces and linear ones.

An automatic transmission of construction equipment is controlled by hydraulic and electronic system for doing in various functions like as shifting and operation. The shifting is operated by the engaged and disengaged clutch motion from hydraulic power. On the shifting process, suitable pressure control to the clutch is required for smooth shifting. Hydraulic control system in the automatic transmission is divided by the pilot control type and the direct control type greatly. The direct control type has an advantage than the pilot control type. Because the structure is simple, the design and the manufacture are having less troubles and the system can be maximized precision pressure control. However, the excellent performance proportional control valve should be used to achieve proper control-ability. In this study, the dynamic analysis model composing the automatic transmission and hydraulic system for forklift truck is presented to simulate the characteristics of hydraulic system about the direct control type. That model is verified the validity compared the results of the testing examination. Parameters of input signal are analyzed to reduce the output torque according to input control signal is affected in shifting characteristic.

본 논문에서는 환자의 산소 민감도와 선호패턴을 고려하여 개인별 산소치료 프로파일을 지정하고, 여기에 따라 자동적으로 시간별 산소압을 조정하여 제공하는 3단 분리형 단격실 산소챔버를 설계한다. 고압산소치료는 대기압보다 높은 100% 산소를 환자에게 제공하는 방법으로 개인에 따라 기압차에 따른 귀의 통증을 호소하는 단점이 있었다. 제안 시스템은 임베디드 시스템을 기반으로 환자의 산소치료 선호패턴 및 치료기록을 DB화하여 환자 맞춤형 산소치료 프로파일을 작성하 고, 환자의 이름만 입력하면 산소챔버가 자동적으로 작성된 프로파일 패턴에 따라 산소압을 자동적으로 조정함으로써 산소 치료 효과를 극대화 할 수 있다. 향후 관리자의 스마트폰과 연동하여 작동하는 산소챔버용 원격관리 시스템으로 확장함으로써 관리의 용이성 및 산소치료의 안전성을 제고하고 부가가치를 극대화 할 수 있기를 기대한다.

In this paper, considering the oxygen sensitivity and preference pattern of the patient, the profile of the oxygen therapy of the individual is specified. And, we design a three-compartment, single compartment oxygen chamber that automatically adjusts the oxygen pressure according to the specified profile. Hyperbaric oxygen therapy is a method of providing patients with 100% oxygen higher than atmospheric pressure for therapeutic purposes. However, there is a disadvantage that the ear pain is caused by the pressure difference depending on the individual. Based on the embedded system, the proposed system creates a patient-tailored oxygen therapy profile by DB of patient's preference patterns and treatment records of oxygen therapy. If only the patient's name is entered, the oxygen chamber system can adjust the oxygen pressure automatically according to the profile pattern to maximize the oxygen treatment effect.

오토바이의 윙커(방향지시등)는 승용차와 달리 주행 시 방향지시등 레버의 자동 리턴 기능이 불가능하여 회전 주행 완료 후 운전자가 수동으로 윙커스위치를 오프(OFF) 조작해야 하므로 운전자의 편의성 및 안전 주행 에 문제가 있다. 본 논문에서는 윙커스위치 조작 없이 자동으로 이륜차의 윙커 점멸 기능을 제어할 수 있는 새로 운 방식의 이륜차용 윙커 리턴 시스템을 제안한다. 교차로 회전 또는 차선 변경의 경우에 윙커스위치의 방향 전환 신호 조작 후 회전이 완료되면 승용차와 같이 윙커 스위치의 점멸 동작이 완료되는 자동 리턴 기능을 구현하였다. 제안된 제어 시스템을 오토바이 실차에 장착 및 테스트하여 이륜차용 윙커 자동 리턴 기능을 확인하였다.

Contrary to passenger cars, the winker of a motorcycle does not have an automatic return function of the turn signal lever. So the driver must manually turn the winker switch off after making turns which causes problems with the driver’s convenience and safe driving. In this paper, we propose a new type of winker control system for motorcycles that can automatically control the winker returning function without operating the winker switch manually. The system was implemented to control the blinking operation as in a passenger car in the case of intersection turn or lane change without manipulating the direction change signal with the winker switch. The proposed control system was installed and tested on a motorcycle to confirm the automatic winker return feature.