• Journal of the KSME
• /
• v.28 no.2
• /
• pp.123-129
• /
• 1988

공학분야에서 널리 사용되고 있는 신호처리 및 해석의 기본이 되는 범용 데이터 수집 소프트웨 어의 기본적인 사항 및 그 개발예에 대해 언급하여 보았다. 데이터 수집장치 및 그를 제어하는 소프트웨어는 신호처리 및 해석을 통하여 국외에서 개발된 시스템보다는 훨씬 저렴한 가격으로 국내에서 개발될 수 있으며 국내에서 쉽게 구할 수 있는 것들로 데이터 수집 시스템 구성이 가 능함을 보였다. 또한 국내 개발 시, 시스템의 개조 및 성능향상이 용이하므로 점차적으로 그 성능 및 정확도를 향상시켜나갈 수 있으며 사용자의 목적에 따른 기능변경이 수월하다는 장점이 있겠다. 이러한 데이터 수집 소프트웨어의 개발시 그 성능을 크게 좌우하는 것은 A/D변환기 및 관련 하드웨어의 성능과 이를 직접 제어하는 기계어 Routine의 수행속도 및 능률이라는 점을 들 수 있겠다. 왜냐하면 데이터 수집기능 및 온라인 처리가 필요한 디지틀 오실로스코프 기능과 같은 일을 수행하는 소프트웨어는 하드웨어와 밀접한 관계가 있으며, 전체 수집 시스템의 성능에 둘 다 큰 영향을 미치게 되기 때문이다. 이러한 것은 하드웨어설계자와 프로그램 작성자와의 충분한 토의 및 상호 기능개선에 의해 해결되어 데이터 수집 시스템의 성능이 크게 향상되어질 수 있으며, 전자기술의 발전으로 인해 하드웨어의 성능이 크게 향상되고 이에 따른 소프트웨어의 개선이 진행됨에 의해 보다 나은 데이터 수집 시스템의 개발이 가능해지리라 사료된다.

• Journal of the Korean Society for Aviation and Aeronautics
• /
• v.28 no.1
• /
• pp.106-114
• /
• 2020

The Lion Air JT610 accident in Indonesia in October 2018, along with the Ethiopian Airline ET302 accident in March 2019, is an significant aircraft accident that detects defects of the B737MAX aircraft. Shortly after the accident, the FAA prohibited operation of the aircraft. This action has affected the market environment of airlines and aircraft manufacturers around the world. In October 2019, Indonesian Traffic Safety Committee released an accident investigation report for Lion Air JT610, which concluded that the causes of the accident were MCAS design defects, lack of education and training, and errors in the repair process. This paper summarizes the flight control system of the B737MAX aircraft, the causes of the accident based on the final accident investigation report, and provides considerations for aircraft design and retrofit.

• Journal of Institute of Control, Robotics and Systems
• /
• v.12 no.9
• /
• pp.945-953
• /
• 2006

Though a fully thermally coupled distillation column consumes less energy than an original column, it is not widely implemented in practice due to its operational difficulty. A new fully thermally coupled distillation column is proposed for the operability improvement, and its performance is investigated. The main improvement is the separation of a main column to give an upper and lower columns and the installation of an intermediate heat exchanger between them to regulate the fluctuation of product compositions. A proper manipulation of column pressure in the separated main columns made easy vapor flow without a compressor. The operability improvement is examined in a hexane process from the dynamic simulation using a commercial design software HYSYS. The simulation results indicate that the coupling among inputs and outputs is loosened to make easy manipulation of product compositions in the proposed distillation system.

• Proceedings of the Korean Society for Bio-Environment Control Conference
• /
• 1999.11a
• /
• pp.225-228
• /
• 1999

기내 조직배양묘의 생육에 가장 큰 영향을 미치는 주요 환경 요인으로 광, 온도, $CO_2$, 배지 등이 있다. 이중 광, 온도 및 $CO_2$ 가스는 기외로 부터 공급을 받거나 제어 할 수 있는 요인으로써 배양체의 생육에 있어 매우 중요하다. 배양 챔버내의 환경 제어는 용이하지만, 배양체에 직접적인 영향을 주는 용기내의 환경 계측은 용이하지 않다. 실제 배양체의 생육에 가장 큰 영향을 미치는 용기 내 환경과 배양 챔버의 환경은 큰 차이를 나타내기 때문에 조직배양용기내의 미기상 환경에 대한 분석은 필요하다. (중략)

• Journal of Bio-Environment Control
• /
• v.22 no.2
• /
• pp.138-145
• /
• 2013

In order to develop the efficient control algorithm of the two-fluid fogging system, cooling experiments for the many different types of fogging cycles were conducted in tomato greenhouses. It showed that the cooling effect was 1.2 to $4.0^{\circ}C$ and the cooling efficiency was 8.2 to 32.9% on average. The cooling efficiency with fogging interval was highest in the case of the fogging cycle of 90 seconds. The cooling efficiency showed a tendency to increase as the fogging time increased and the stopping time decreased. As the spray rate of fog in the two-fluid fogging system increased, there was a tendency for the cooling efficiency to improve. However, as the inside air approaches its saturation level, even though the spray rate of fog increases, it does not lead to further evaporation. Thus, it can be inferred that increasing the spray rate of fog before the inside air reaches the saturation level could make higher the cooling efficiency. As cooling efficiency increases, the saturation deficit of inside air decreased and the difference between absolute humidity of inside and outside air increased. The more fog evaporated, the difference between absolute humidity of inside and outside air tended to increase and as the result, the discharge of vapor due to ventilation occurs more easily, which again lead to an increase in the evaporation rate and ultimately increase in the cooling efficiency. Regression analysis result on the saturation deficit of inside air showed that the fogging time needed to change of saturation deficit of $10g{\cdot}kg^{-1}$ was 120 seconds and stopping time was 60 seconds. But in order to decrease the amplitude of temperature and to increase the cooling efficiency, the fluctuation range of saturation deficit was set to $5g{\cdot}kg^{-1}$ and we decided that the fogging-stopping time of 60-30 seconds was more appropriate. Control types of two-fluid fogging systems were classified as computer control or simple control, and their control algorithms were derived. We recommend that if the two-fluid fogging system is controlled by manipulating only the set point of temperature, humidity, and on-off time, it would be best to set up the on-off time at 60-30 seconds in time control, the lower limit of air temperature at 30 to $32^{\circ}C$ and the upper limit of relative humidity at 85 to 90%.

• Journal of Animal Environmental Science
• /
• v.17 no.sup
• /
• pp.43-50
• /
• 2011

This study was conducted to verify the effect of chlorine dioxide ($ClO_2$) on odor reduction at a commercial swine facility consisting of a windowless piglet barn and a grower/fattening barn. The windowless piglet barn used a duct ventilation system. Air velocity at very below the upper duct was 4.53 m/s. Air velocity at the lower space around the living space of pigs in the grower/fattening barn was 0.26 m/s. $NH_3$ concentration was around 9ppm and less than 3 ppm before and after the $ClO_2$ spraying, respectively, which was over 70% reduction. There was no $H_2S$ detection. $NH_3$ concentrations measured in the windowless grower/fattening barn and at the exhausted air were 26 ppm and 11ppm, respectively. $NH_3$ concentration at a biocurtain outside was less than 1 ppm. Hence, $ClO_2$ spraying at windowless barns was effectively decreased malodor such as $NH_3$.

• Journal of the Korean Institute of Gas
• /
• v.25 no.3
• /
• pp.27-38
• /
• 2021

We devised the system to automatically shutdown the boiler and to fundamentally block the harmful gases, including carbon monoxide, into the indoor when the exhaust system swerves: (1) The discharge pressure of the exhaust gas decreases when the exhaust pipe is disconnected. The monitoring system of the exhaust pipe is implemented by measuring the output voltage of APS(Air Pressure Sensor) installed to control the amount of combustion air. (2) The operating software was modified so that when the system recognizes the fault condition of a flue pipe, the boiler control unit displays the fault status on the indoor regulator while shutting down the boiler. In accordance with the ventilation facility standards in the "Rules for Building Equipment Standards" by the Ministry of Land, Infrastructure and Transport, experiments were conducted to ventilate indoor air. When carbon monoxide leaked in worst-case scenario, it was possible to prevent poisoning accidents. However, since 2013, the number of indoor air exchange times has been mitigated from 0.7 to 0.5 times per hour. We observed the concentration exceeding TWA 30 ppm occasionally and thus recommend to reinforce this criterion. In conclusion, if the flue pipe fault detection and the indoor air ventilation system are introduced, carbon monoxide poisoning accidents are expected to decrease significantly. Also when the manufacturing and inspection steps, the correct installation and repair are supplemented with the user's attention in missing flue, it will be served to prevent human casualties from carbon monoxide poisoning.

• Journal of Korean Society of Disaster and Security
• /
• v.12 no.2
• /
• pp.47-56
• /
• 2019

Recently, in order to overcome the difficulty of entering a fire source due to the occurrence of a large amount of smoke in the event of a fire in a parking lot, it has used that a method of discharge smoke using air supply, exhaust fans and jet fans installed for ventilation of parking lots. In this study, the variation of flow in the smoke layer was observed using CCTV under two conditions, in which only the air supply fan operates and the manned fan operates together, and the temperature around the plume was compared to Albert eq. to assess its suitability as a parking lot ventilation performance evaluation method. As a result, it was found that the smoke layer could be disturbed if the Jet Fan was operated at the same time, which could lead to the possibility of an initial evacuation disturbance. However, the additional operation of the Jet Fan has been confirmed by the observation CCTV that the emission performance is improved, which is believed to help conduct the suppression operation. The temperature around the plume was measured and compared to Alpert eq, and was analyzed to be about $2^{\circ}C$ lower at the center axis of the plume and $9.0^{\circ}C$ higher at 8 m in the direction of the discharge of smoke. The results of temperature measurements around the plume were lower than the maximum temperature expected in AS 4391 and did not exceed the expected temperature risk caused by the experiment. As with these results, the temperature risk from the progression of hot smoke tests is foreseeable, so it will be available as one of the general evaluation methods for assessing smoke control performance in a parking lot without relevant criteria.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.12 no.3
• /
• pp.465-470
• /
• 2017

This paper designs and implements a smart garden system using probabilistic filter algorithm using SLAM that can be used in apartment or veranda. To do this, we used Arduino and environtal sensors, which are open hardware controllers, and designed to control and observe automatic water supply, lighting, and growth monitoring with three wireless systems (Bluetooth, Ethernet, WiFi). This system has been developed to make it possible to use it in an indoor space such as an apartment, rather than a large-scale cultivation system such as a conventional plant factory which has already been widely used. The developed system collects environmental data by using soil sensor, illuminance sensor, humidity sensor and temperature sensor as well as control through smartphone app, analyzes the collected data, and controls water pump, LED lamp, air ventilation fan and so on. As a wireless remote control method, we implemented Bluetooth, Ethernet and WiFi. Finally, it is designed for users to enable remote control and monitoring when the user is not in the house.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2007.10a
• /
• pp.897-900
• /
• 2007

This paper presents a study on the DSP controller and IGBT inverter driver design for the power-by-wire(PBW) system using BLDC servo motor. This BLDC servo motor system was realized with DSP(Digital Signal Processor) and IGBT inveter module. The PBW system needs speed control of servo motor for linear thrust action. This paper implements a servo controller with vector control and min-max PWM technique. As CPU of controller, TMS320F2812 DSP was adopted because it has PWM(Pulse Width Modulation) waveform generator, A/D(Analog to Digital) converter, SPI( Serial Peripheral Interface) port and many input/output port etc.