• Title/Summary/Keyword: Automatic environmental control

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BASIS RESEARCH ON NOISE CONTROL OF HEAD-FEEDING TYPE COMBINE HARVESTER USING SOUND INTENSITY METHOD

  • Sasao, A.;Iwasa, M.
    • Proceedings of the Korean Society for Agricultural Machinery Conference
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    • 1993.10a
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    • pp.752-760
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    • 1993
  • We research ed on the noise control of a head feeding type combine harvester. It is a kind of combine harvester developed in Japan. And at present, it is used by most Japanese farmer. For a head-feeding type combine harvester it is very difficult to determine the sources of noise because it is a combination of reapers and automatic , threshers and several running parts. However we succeeded in finding out the sound sources of combine harvesters and analyzing their sound by the using sound intensity method. The sound intensity Method is a very up-to-date method to measure and analyze Sound Intensity Levels and sound directions at several measuring point sin a specified area. In this research, first a conventional sound level measurement method is used and secondly the sound intensity method. The first method shows a rather great limitation in allowed exposure duration. The second method shows pin-points the engine itself as being the main source of noise, causing sound flows a ross the operator's seat.

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Study on the Water Quality Control of Water Supply the Reside: Effects of Chlorinations (상수도의 수질관리와 타소소독의 잔류효과에 관한 연구)

  • 유귀현
    • Journal of environmental and Sanitary engineering
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    • v.6 no.2
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    • pp.33-47
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    • 1991
  • 1. Water supply treatment plants personnel could not test the water quality control, because most of them rely on the provincial health laboratories about water quality rely rant test. However, in future, plants have to been provided the facilities and equipment of water quality laboratory. 2. Chlorination methods are 89.5% of liquid chlorine and 10.5% of solid chlorine, and the cost per 1 $\m^{3}$ of chlorination is about 1.30 won which chlorination cost is very cheap as 1/142 of drinking water production cost. Input method of chlorine is 35% of automatic method, 56% of semi-automatic, and 9% of other methods, and this is no problem 3. Residual effects of chlorination, in the case of distilled water as a standardized material and 0.2 ppm of seperated residual chlorine, were continued 32 hours in $0^{\circ}C$, and 25 hour in $20^{\circ}C$, of water temperature and in the case of 0.4 ppm of seperated residual chlorine were continued 47 hours in $0^{\circ}C$ and 23 hours in $20^{\circ}C$. 4. In the case of 4 ppm of seperated residual chlorine, residual effects were continued 23 hours in $5^{\circ}C$, 90 hours in $10^{\circ}C$, 78 hours in $15^{\circ}C$, and 60 hours in $20^{\circ}C$ : by the temper; lure of water, continuing residual effects of chlorination are different, so we have to car for the warm season chlorination in the hider temperature. 5. Chlorination effects of drinking waters in the case of 0.4 ppm of seperated residual chlorine were continued 237 hours in $22^{\circ}C$ water : and in the case of rechlorination as 4 ppm of residual chlorine, continued 71 hours in $22^{\circ}C$ water.

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Development of a smart rain gauge system for continuous and accurate observations of light and heavy rainfall

  • Han, Byungjoo;Oh, Yeontaek;Nguyen, Hoang Hai;Jung, Woosung;Shin, Daeyun
    • Proceedings of the Korea Water Resources Association Conference
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    • 2022.05a
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    • pp.334-334
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    • 2022
  • Improvement of old-fashioned rain gauge systems for automatic, timely, continuous, and accurate precipitation observation is highly essential for weather/climate prediction and natural hazards early warning, since the occurrence frequency and intensity of heavy and extreme precipitation events (especially floods) are recently getting more increase and severe worldwide due to climate change. Although rain gauge accuracy of 0.1 mm is recommended by the World Meteorological Organization (WMO), the traditional rain gauges in both weighting and tipping bucket types are often unable to meet that demand due to several existing technical limitations together with higher production and maintenance costs. Therefore, we aim to introduce a newly developed and cost-effective hybrid rain gauge system at 0.1 mm accuracy that combines advantages of weighting and tipping bucket types for continuous, automatic, and accurate precipitation observation, where the errors from long-term load cells and external environmental sources (e.g., winds) can be removed via an automatic drainage system and artificial intelligence-based data quality control procedure. Our rain gauge system consists of an instrument unit for measuring precipitation, a communication unit for transmitting and receiving measured precipitation signals, and a database unit for storing, processing, and analyzing precipitation data. This newly developed rain gauge was designed according to the weather instrument criteria, where precipitation amounts filled into the tipping bucket are measured considering the receiver's diameter, the maximum measurement of precipitation, drainage time, and the conductivity marking. Moreover, it is also designed to transmit the measured precipitation data stored in the PCB through RS232, RS485, and TCP/IP, together with connecting to the data logger to enable data collection and analysis based on user needs. Preliminary results from a comparison with an existing 1.0-mm tipping bucket rain gauge indicated that our developed rain gauge has an excellent performance in continuous precipitation observation with higher measurement accuracy, more correct precipitation days observed (120 days), and a lower error of roughly 27 mm occurred during the measurement period.

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Feasibility Study on Installation of Individual Room Control Ventilation in Apartment House (공동주택의 실별 제어환기 도입 타당성 분석)

  • Kim, Jung-Yup;Shin, Hyun-Joon;Kwon, Yong-Il;Yun, Young-Woo;Cho, Chun-Sik
    • Proceedings of the SAREK Conference
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    • 2009.06a
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    • pp.502-507
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    • 2009
  • Trend of mechanical ventilation system applied to apartment house is introduced and feasibility study on installation of the individual room control ventilation as energy-saving method is carried out through field experiment. While initial cost of installation for the individual room control ventilation increases, the running cost is lower than the individual household control ventilation due to automatic flow rate control and reduction of fan power, and the management cost also decreases due to extension of use life of components. As the results of field experiment on $115m^2$-type apartment house, the individual room control ventilation could save the amount of 1,459.5Wh/day when compared with the individual room control ventilation

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A Study on the Improvement of Indoor Environment in the Underground Parking Lot of Apartments in Jeonju City (전주시 공동주택 지하주차장의 실내환경 개선에 관한 연구)

  • Jung, Jaeyoun;Jeong, Insoo;Bao, Wei
    • Journal of the Korean Institute of Rural Architecture
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    • v.22 no.1
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    • pp.1-12
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    • 2020
  • The main purpose of the research is to prevent residents who are using underground parking lot from being exposed to pollusion, and to allow them to enjoy clean indoor environment. The study subject for the research are underground parking lots in 20 different apartments, 4 of them were constructed before 2000, 10 were constructed from 2000-2010, and the rest were constructed after 2010. By analyzing the air quality in these underground parking lots, we found out that O3, NO2, CO, PM10, Radon in all parking lots were not excessive compared to the standard limit. TVOC rate was measured with the value in between 312 ~ 2,137㎍/m3, with CO2 value in between 193~1,824 ppm, and HCHO with the value in between 0.01~1.52ppm. The lightning system in underground parking lots in apartments constructed before 2000 were using manual light control system, while automatic light control system was used in all apartments constructed after 2000, and the brightness of parking lots in apartments constructed before 2000 was quite low. The apartments constructed after 2000 are performing cleaning and ventilation due to management agreement, while the apartments constructed before 2000 are not performing regular cleaning and there was no mechanical ventilation system installed. The difference of indoor air quality was significant seasonally, daily, and yearly (year of construction), while illuminance was significantly different yearly.

Real Time 1/3 Octave Band Control System for High Intensity Acoustic Chamber (음향 챔버 내부의 1/3 옥타브 스펙트럼 실시간 제어 시스템)

  • Kim, Young-Key;Kim, Hong-Bae;Moon, Sang-Mu;Woo, Sung-Hyun;Lee, Sang-Seol
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2002.11b
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    • pp.881-885
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    • 2002
  • This paper presents the performance and the algorithm of a 1/3-octave band spectrum control system. The system is developed to provide various spectrums in a high intensity acoustic chamber. The required spectrum, which usually comes from launch vehicle company, starts from 25Hz band and ends 10kHz band. Automatic spectrum control system is preferred since the system requires short settling time to guarantee the safety of test objects and to reduce the amount of operating gas. The developed system adapted a PCI data-acquisition/signal-generation board installed in a personal computer to implement whole control logic. The control software used three cascade digital Butterworth filters using software. The filers are designed following ANSI S1.11 standard to implement 1/3 octave band filter bank. The graphical user interface of the system guides the user to follow standard operation procedure. The averaged control spectrum showed less than 0.05 dB in every running 1/3-octave band.

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Numerical Simulations of the local circulation in coastal area using Four-Dimensional Data Assimilation Technique (4차원 자료동화 기법을 이용한 해안가 대기 순환의 수치 실험)

  • Kim, Cheol-Hee;Song, Chang-Keun
    • Journal of Environmental Impact Assessment
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    • v.11 no.2
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    • pp.79-91
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    • 2002
  • Four dimensional data assimilation (FDDA) technique was considered for 3 dimensional wind field in coastal area and a set of 3 numerical experiments including control experiments has been tested for the case of the synoptic weather pattern of the weak northerly geostrophic wind with the cloud amount of less than 5/10 in autumn. A three dimensional land and sea breeze model with the sea surface temperature (SST) of 290K was performed without nudging the observed wind field and surface temperature of AWS (Automatic Weather System) for the control experiment. The results of the control experiment showed that the horizontal temperature gradient across the coastline was weakly simulated so that the strength of the sea breeze in the model was much weaker than that of observed one. The experiment with only observed horizontal wind field showed that both the pattern of local change of wind direction and the times of starting and ending of the land-sea breeze were fairly well simulated. However, the horizontal wind speed and vertical motion in the convergence zone were weakly simulated. The experiment with nudgings of both the surface temperature and wind speed showed that both the pattern of local change of wind direction and the times of starting and ending of the land-sea breeze were fairly well simulated even though the ending time of the sea breeze was delayed due to oversimulated temperature gradient along the shoreline.

An Object Recognition Performance Improvement of Automatic Door using Ultrasonic Sensor (초음파 센서를 이용한 자동문의 물체인식 성능개선)

  • Kim, Gi-Doo;Won, Seo-Yeon;Kim, Hie-Sik
    • Journal of the Institute of Electronics and Information Engineers
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    • v.54 no.3
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    • pp.97-107
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    • 2017
  • In the field of automatic door, the infrared rays and microwave sensor are much used as the important components in charge of the motor's operation control of open and close through the incoming signal of object recognition. In case of existing system that the sensor of the infrared rays and microwave are applied to the automatic door, there are many malfunctions by the infrared rays and visible rays of the sun. Because the automatic doors are usually installed outside of building in state of exposure. The environmental change by temperature difference occurs the noise of object recognition detection signal. With this problem, the hardware fault that the detection sensor is unable to follow the object moving rapidly within detection area makes the sensing blind spot. This fault should be improved as soon as possible. Because It influences safety of passengers who use the automatic doors. This paper conducted an experiment to improve the detection area by installing extra ultrasonic sensor besides existing detection sensor. So, this paper realize the computing circuit and detection algorithm which can correctly and rapidly process the access route of objects moving fast and the location area of fixed obstacles by applying detection and advantages of ultrasonic signal to the automatic doors. With this, It is proved that the automatic door applying ultrasonic sensor is improved detection area of blind spot sensing through field test and improvement plan is proposed.

Estimating Optimal Parameters of Artificial Neural Networks for the Daily Forecasting of the Chlorophyll-a in a Reservoir (호소내 Chl-a의 일단위 예측을 위한 신경망 모형의 적정 파라미터 평가)

  • Yeon, Insung;Hong, Jiyoung;Mun, Hyunsaing
    • Journal of Korean Society on Water Environment
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    • v.27 no.4
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    • pp.533-541
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    • 2011
  • Algal blooms have caused problems for drinking water as well as eutrophication. However it is difficult to control algal blooms by current warning manual in rainy season because the algal blooms happen in a few days. The water quality data, which have high correlations with Chlorophyll-a on Daecheongho station, were analyzed and chosen as input data of Artificial Neural Networks (ANN) for training pattern changes. ANN was applied to early forecasting of algal blooms, and ANN was assessed by forecasting errors. Water temperature, pH and Dissolved oxygen were important factors in the cross correlation analysis. Some water quality items like Total phosphorus and Total nitrogen showed similar pattern to the Chlorophyll-a changes with time lag. ANN model (No. 3), which was calibrated by water temperature, pH and DO data, showed lowest error. The combination of 1 day, 3 days, 7 days forecasting makes outputs more stable. When automatic monitoring data were used for algal bloom forecasting in Daecheong reservoir, ANN model must be trained by just input data which have high correlation with Chlorophyll-a concentration. Modular type model, which is combined with the output of each model, can be effectively used for stable forecasting.

Optimal Control Design for Automatic Ship Berthing by Using Bow and Stern Thrusters

  • Bui, Van Phuoc;Jeong, Jeong-Soon;Kim, Young-Bok;Kim, Dong-Wook
    • Journal of Ocean Engineering and Technology
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    • v.24 no.2
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    • pp.10-17
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    • 2010
  • Conventionally, because it is difficult to control a ship in shallow water and because attempting to do so creates unwanted environmental effects, maneuvering ships in the harbor area for berthing is usually done with the assistance of tugboats. In this paper, we propose a new method for berthing ships automatically by using bow and stern thrusters. Specifically, a steering motion model of a ship is considered, and parameters in the equation are evaluated by the system identification technique. An optimal controller based on observations was designed from the linearization of the non-linear ship motion in the horizontal plane. It is used to reduce the uncertainty about the ship's dynamics and reduce measurement requirements. The performance of the controller was also analyzed for its robustness relative to avoiding disturbing the environment due to winds, currents, and wave-drift forces. Experiments were conducted to estimate the potential for identifying result and the design of the controller. Specifically, in this paper, the system modeling and tracking control approach are discussed based on a two-degree-of-freedom (2DOF) servo-system design.