RISS 학술연구정보서비스

검색
다국어 입력

http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.

변환된 중국어를 복사하여 사용하시면 됩니다.

예시)
  • 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
  • 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
닫기
    인기검색어 순위 펼치기

    RISS 인기검색어

      검색결과 좁혀 보기

      선택해제
      • 좁혀본 항목 보기순서

        • 원문유무
        • 원문제공처
        • 등재정보
        • 학술지명
        • 주제분류
        • 발행연도
        • 작성언어
        • 저자
          펼치기

      오늘 본 자료

      • 오늘 본 자료가 없습니다.
      더보기
      • 무료
      • 기관 내 무료
      • 유료
      • KCI등재

        Evaluation of pepper seedling growth according to the growing period and tray for automatic transplanting

        Nafiul Islam,Md Zafar Iqbal,ALI MOHAMMOD,이예슬,우재근,최일수,정선옥 충남대학교 농업과학연구소 2021 Korean Journal of Agricultural Science Vol.48 No.4

        The effective growth of pepper seedlings relies on the growing period and tray used, which both aim to minimize seedling damage during the transplantation process. Therefore, the objective of this study was to evaluate the effect of red and green pepper seedling growth in plug and cylindrical paper pot (CPP) trays with different growth periods of the seedlings. Two different seedling growth trays were used for the two varieties of pepper seedlings in the same growing media. The pepper seedling growth rates were investigated at 15, 30, and 45 days for each of variety. Important parameters, e.g., the plant height, fresh weight for the plant and root, number of leaves, leaf length and width, and leaf chlorophyll contents, were measured. During the experiment, the CPP tray maintained uniform seedling growth as compared to the plug tray. CPP trays ensured the height of the seedling, with these results 0.84 to 1.6 times higher than those of the plug tray for all conditions, indicating the good quality of the pepper seedlings. The shoot and root weights were found to be greater with more leaves in the CPP tray seedlings for 45 days compared to the seedlings grown in the plug tray, whereas the green pepper variety showed a greater leaf ratio than the red pepper seedlings. The analysis of pepper seedling growth presented in this study will guide the selection of suitable growth trays and seedling periods for farmers when they undertake automatic pepper transplantation in the field.

      • 자주식 양파정식기 슬라이딩 메쉬형 기어박스의 동력전달 해석

        이슬람나피울 ( Md Nafiul Islam ),알리모하마드 ( Mohammod Ali ),키라가샤피크 ( Shafik Kiraga ),초두리밀론 ( Milon Chowdhury ),권행주 ( Haing-ju Kwon ),정선옥 ( Sun-ok Chung ) 한국농업기계학회 2021 한국농업기계학회 학술발표논문집 Vol.26 No.1

        An appropriate gearbox selection is essential to avoid transmission losses and convey the engine power to the transplanter components efficiently. Therefore, the objective of this research was to simulate the power transmission of a self-propelled onion transplanter gearbox for calculating the power loss and efficiency. The automatic transplanter power transmission scheme consists of wheels, and dibbling mechanism, and picking mechanism. A computer-aided gear efficiency calculation software package was used to develop a three-dimensional simulation model for the automatic onion transplanter. A V-belt with pulley and nine gear stages sliding mesh type gearbox were used to transmit power from engine to wheel and other transplanter components. The last two gear sets were used as dibbling and picking mechanism gear shafts, respectively. The transmission load was measured at the input shaft of the gearbox, and the driving axle load was measured at the final drive shaft. The load measurements were made at three-speed levels. The input power of the gearbox was 1.7 kW, and the last stage of power (picking scheme) was found as 0.8 kW. The overall efficiency of this gearbox was found as 83.39%. The outcomes of the research would provide a significant reference for the development a power transmission scheme for efficient automatic onion transplanting.

      • Kinematic Analysis of a Picking Device for a Plug Seedling Pepper Transplanter

        ( Nafiul Islam ),( Zafar Iqbal ),( Ye-seul Lee ),( Shaha Nur Kabir ),( Sun-ok Chung ),( Yong-joo Kim ),( Tae-gyoung Kang ),( Kyu-sik Park ) 한국농업기계학회 2018 한국농업기계학회 학술발표논문집 Vol.23 No.1

        The objective of this research was to simulate and analyze of a plug seedling transplanter picking device for determining picking device parameters. The picking device consisted of a manipulator, grippers, and a picking stand. Manipulator consisted of two parallel cams and cranks where two cranks drove the gripper ‘y’ direction and two cams ‘x’ direction. Kinematic analysis was conducted and checked the physical constraint. From the kinematic analysis, among six (6) trials, the selected lengths of picking stand and manipulator with grippers were found as 350 mm and 380 mm, respectively. The velocity of the gripper in ‘y’ and ‘x’ directions were found as 0.09 m/s to 0.47 m/s and 0.3 m/s to 1.2 m/s, respectively. The outcomes of the research would provide a significant reference for the development a picking scheme for efficient pepper transplanting.

      • KCI등재

        Performance Evaluation of a Suspension-Type Dehumidifier with a Heating Module for Smart Greenhouses

        Md Nafiul Islam,Md Zafar Iqbal,ALI MOHAMMOD,장보은,Milon Chowdhury,Md Shaha Nur Kabir,장승호,정선옥 한국농업기계학회 2020 바이오시스템공학 Vol.45 No.3

        Purpose The management of the temperature and humidity inside greenhouses is essential for optimum crop growth. The temperature and humidity statuses extensively depend on the performance of dehumidifiers and heaters in the greenhouses. The objective of this study was to evaluate the performance of a small-scale suspension-type dehumidifier with a heating module in terms of temperature and humidity changes over time, and monitoring and controlling the status of individual actuating components in summer and winter. Methods The prototype consisted of a dehumidifier, a fan, and a heating module. Twenty-seven temperature and humidity sensor nodes were placed in three layers (top, middle, and bottom) and in three sections (front, center, and rear sides) for monitoring the temperature and humidity statuses. Two additional temperature and humidity sensor nodes were placed in front of the module and outside the greenhouses. An on/off controller was used to manage the temperature and humidity during the operation of the dehumidifier. Results Remote monitoring and controlling was successfully achieved to operate the dehumidifier with a heating module without interruption during the experiments. The time response and change results confirmed the satisfactory performance of the on/off control. The power consumption values varied depending on the status of the actuators. When the dehumidifier, fan, and heater were turned on, the average power consumption values were 556.64 ± 1.94, 125.80 ± 1.26, and 3779.60 ± 2.24 W, respectively. The temperature and humidity showed a considerable amount of spatial and vertical variability, and the temperature and humidity changes were greater in the middle section than in the other sections in both the summer and winter greenhouses. Conclusion The outcomes of the research support the need for small-scale suspension-type dehumidifiers for region-specific temperature and humidity management, and may inform possible improvement of the prototype.

      • Variability Analysis of Relative Humidity during Operation of a Dehumidifier in a Closed Chamber and a Small Plastic Greenhouse

        ( Md. Nafiul Islam ),( Md. Zafar Iqbal ),( Bo-eun Jang ),( Md. Shaha Nur Kabir ),( Hyeon-tae Kim ),( Sun-ok Chung ) 한국농업기계학회 2019 한국농업기계학회 학술발표논문집 Vol.24 No.1

        Analysis of humidity variations inside the greenhouse is important for optimum growth and controlling the diseases and physiological disorders of plant. The objective of this study was to analyze the vertical and spatial variability of humidity inside a closed chamber and a small plastic greenhouse to evaluate the performance of a dehumidifier. In this study, a 4-kW dehumidifier was used for dehumidification in a closed chamber (5.7m×2.9m×2.5m) and a plastic small greenhouse (7m×5m×3m). In this experiment, the dehumidification range was from 90% to 70% and 80% to 70% with three replications. Before the dehumidification experiment, the humidity of the chamber and greenhouse was increased using the additional humidifier and then mixed the humidity well by using an air mixer. Each experiment was started after the chamber humidity level goes in a stable condition. A total twenty-seven (27) temperature and humidity sensor nodes were uniformly placed at three sections such as front, middle, and rear parts of the greenhouse, placing three (3) sensors in the top, middle, and bottom positions at each section. Additional two temperature and humidity sensor nodes were placed in front of the heater and outside of the greenhouse. Sensor nodes were composed of Arduino UNO micro-controller and nRF24L01 2.4 GHz radio/wireless transceivers modules were used for communication. The operational time for average dehumidification was recorded as 70 min and 30 min for 90% to 70% and 80% to 70% humidity range respectively for the closed chamber experiment. In the plastic small greenhouse, the operational time for average dehumidification was recorded as 30 min and 15 min for 90% to 70% and 80% to 70% humidity range respectively. Results of this study showed the vertical and spatial variability of humidity inside the experimented chamber and greenhouse. Further study would be necessary for the development of a control algorithm of the dehumidifier with a heating module in various greenhouses.

      • KCI등재

        Performance Evaluation of Trenchless Subsurface Drainage Piping Machine

        Md Nafiul Islam,Md Zafar Iqbal,Md. Shaha Nur Kabir,정기열,문동해,정선옥 한국농업기계학회 2019 바이오시스템공학 Vol.44 No.4

        Purpose Subsurface pipe drainage can ensure consistent and profitable crop production in poorly drained agricultural regions to remove excess water from the agriculture field. However, improvement is needed in the drainage pipe installation method for the stable production of field crops. The objective of this research was to conduct a performance evaluation of a trenchless subsurface drainage piping machine in terms of pulling force requirement and pipe laying depth uniformity to facilitate the maintenance of soil water control with minimum labor. Methods Two experiment fields were selected considering the physical properties of soil, i.e., silty loam and silty clay loam fields. A load cell and a distance-measuring sensor were used to measure the pulling force and pipe burial depth uniformity, respectively, at two operation depths (40 cm and 45 cm) in both fields. The soil properties (bulk density, cone index, porosity, and soil water content) were measured at various depths (up to 55 cm) from the soil surface. Results The average pulling forces were found to be 6.78 ± 1.35 kN and 7.36 ± 1.55 kN at a depth of 40 cm and 10.07 ± 1.17 kN and 15.49 ± 1.09 kN at a depth of 45 cm for silty loam field and silty clay loam field, respectively. The average laying depths at the laying depth of 40 cm were 40.07 ± 0.30 cm and 40.34 ± 0.33 cm and those at the laying depth of 45 cm were 45.5 ± 0.22 cm and 45.24 ± 0.22 cm for silty loam field and silty clay loam field, respectively. The laying depth condition of 45 cm showed relatively better uniformity than the condition of 40 cm. Conclusions The outcomes of the research can provide a useful reference for the subsurface pipe installation guidelines of a trenchless subsurface drainage piping machine for the pipe drainage network.

      • 농업 4륜 전기 자동차 설계를 위한 환감 기어의 부하 분석

        알리모하마드 ( Mohammod Ali ),이슬람나피울 ( Md. Nafiul Islam ),레자나심 ( Md Nasim Reza ),초두리밀론 ( Milon Chowdhury ),이슬람수마이야 ( Sumaiya Islam ),이현석 ( Hyun-seok Lee ),정선옥 ( Sun-ok Chung ) 한국농업기계학회 2021 한국농업기계학회 학술발표논문집 Vol.26 No.1

        The load analysis of gears is a major challenge to ensure the reliability of the power transmission system of the all-wheel-drive electric vehicle. It is necessary to select the proper material and face width for design the reduction gears to avoid its failure during field operations. Therefore, this study aimed to investigate the suitable materials and dimensions, to evaluate the fatigue life regarding the level of damage. A field experiment was conducted on the off-road conditions following the driving speeds. A load (torque) measurement method was established to collect the torque data using torque sensors and data acquisition systems. A load duration distribution (LDD) method was used to analyze the torque data to examine the cyclic load characteristics. The Palmgren-Miner cumulative damage model was used to determine the fatigue damage level of the reduction gears. The hypothetic fatigue life was recorded up to 2500 hours that satisfied the actual service life of the agricultural vehicle. In order to the analyses, the steel material ‘SCr420H’ with a 5 mm face width gear was suitable for a 10-year vehicle service life. The results presented in this study can suggest the service life of a four-wheeled electric vehicle for agricultural use.

      • KCI등재

        Sensor-Based Nutrient Recirculation for Aeroponic Lettuce Cultivation

        Chowdhury Milon,ISLAM MD NAFIUL,Reza Md Nasim,ALI MOHAMMOD,Rasool Kamal,Kiraga Shafik,이대현,정선옥 한국농업기계학회 2021 바이오시스템공학 Vol.46 No.1

        Purpose The objective of this study was to investigate the effects of used-nutrient solution recirculation on nutrient efficiency improvement and reduction of environmental pollution of an ion-selective electrodes (ISEs)-based recycle-type aeroponic crop cultivation system. Methods A recycle-type aeroponic crop cultivation test bench was fabricated, which consisted of K+, NO3-, and Ca2+ ISEs, pH, and EC sensor, and lettuce were cultivated for inspecting the nutrient solution recirculation process. The specific growth rate of lettuce was evaluated. Different percentages of the used-solution (20%, 40%, 60%, 80%, and 100% of the target volume) were recirculated to find a proper recirculation volume for maintaining the target nutrient level with the minimum supply of stock solutions. The nutrient saving percentage was determined by comparing the nutrient solution requirement with the open-type aeroponic system and open-field cultivation practices. Reduction of environmental pollution was assessed based on the possible environmental pollutions (i.e., surface water pollution, groundwater contamination, and contaminant deposition in the human body), which could be occurred by the direct discharge of the hydroponic nutrient solution. Results The minimum amount of stock solutions were required during the 60%used-solution recirculation. The nutrient solution requirement of the recycle-type aeroponic system was almost 3 to 5 times less than the open-type aeroponic system, and 3 to 6 times less than open-field cultivation based on nutrient consumption rates at different growth stages. An open-type aeroponic system might require more nutrient solution than the open-field cultivation practices based on the frequency of nutrient solution supply in the crop root zone. Although, the discharged nutrient solution increased the K+, NO3-, andCa2+ ion levels a little in the considered surface water reservoir, groundwater, and human body, long-term discharge of the high concentrated hydroponic nutrient solution would be hazardous. Conclusion The findings of this study showed that the nutrient saving efficiency of a recycle-type crop cultivation system is higher compared to the open-type and conventional cultivation practices, which can minimize the cultivation cost notably, and the environmental pollutions can be reduced significantly through the sensor-based nutrient management.

      • KCI등재

        Monitoring the Operating Status of an Automatic Harmful Fly Collector for Smart Greenhouses

        Zafar Iqbal,Nafiul Islam,장보은,ALI MOHAMMOD,Shaha Nur Kabir,이대현,나규동,박수복,정선옥 한국농업기계학회 2019 바이오시스템공학 Vol.44 No.4

        Purpose Harmful flies are one of the major threats to greenhouse crop cultivation in terms of economic loss. Controlling flies in an environmentally friendly manner is preferable to utilizing chemicals. Therefore, the purpose of this study was to develop a system for monitoring the operating status and controlling the major components of an information and communication technology-based eco-friendly harmful fly collector to ensure smooth operation. Methods The target harmful fly collector consists of two fly collection chambers with a blower, electric bracket, UV lamp, and LED lamp in each chamber. The collector is moved between plant rows in a greenhouse by a motor on a pipe rail. The operating status monitoring system includes an onsite node and remote node, which consist of microcontrollers, current sensors, relays, radio frequency modules, and manually controlled signal providers for monitoring and controlling the operations of the collector. Results The proposed monitoring system allows the operating conditions of the rail motor to be identified accurately as high, mid, low, and back speeds based on power consumption levels of 182.63 ± 2.83 W, 169.58 ± 2.77 W, 157.09 ± 3.05 W, and 122.71 ± 3.51 W, respectively. The operating status of the blowers, LED lamps, and UV lamps can be determined based on power consumption levels of 144.46 ± 1.35 W, 63.45 ± 0.93 W, and 65.02 ± 0.95 W, respectively. The electric bracket consumes up to 245.3 W of power in the presence of any harmful flies. Remote monitoring and control were successfully implemented to operate each component of the collector without failure during our experiments. Conclusions The system developed in this study can effectively secure the stable operations of environmentally friendly harmful fly collectors in smart greenhouses.

      • Working Speed Analysis of a Gear Driven Hopper Type Dibbling Mechanism for a Two-row Pepper Transplanter

        ( Zafar Iqbal ),( Nafiul Islam ),( Ye-seul Lee ),( Shaha Nur Kabir ),( Sun-ok Chung ),( Yong-joo Kim ),( Tae-gyoung Kang ),( Kyu-sik Park ) 한국농업기계학회 2018 한국농업기계학회 학술발표논문집 Vol.23 No.1

        Objective of this research was to perform speed analysis of a hopper type dibbling device for determining the suitable planting speed with forward speed of transplanter using design and simulation software packages. Among eight (8) combinations of link lengths such as primary arm, connecting arms and dibbling hoppers, a suitable combination was derived as 240 mm, 70 mm and 153 mm respectively for a dibbling mechanism. From the simulation, dia of spur gears was found in primary arm as 96 mm and 48 mm and in connecting arm as 28 mm and 56 mm respectively. Through the speed analysis, it was found that the selected dibbling device could plant 120 seedlings/min in a row with a planting interval of 20 cm for 60 rpm of the primary arm. The falling height of the seedling from the conveying belt to dibbling hopper was kept as 75 mm. This dibbling device could work with forward speed range 0.3 m/s - 0.5 m/s with planting depth of 50 ± 5 mm. Results of this study would provide information for better design of the dibbling mechanism, but field test would be required for the validation of the simulation.

      연관 검색어 추천

      이 검색어로 많이 본 자료

      활용도 높은 자료

      해외이동버튼