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Virtual Prototyping of Automated System for Adjustable Row Spacing of Hydroponic Gullies in Multilayer Plant Factory

  • Ashtiani-Araghi, Alireza;Lee, Chungu;Cho, Seong-In;Rhee, Joong-Yong
    • Journal of Biosystems Engineering
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    • v.40 no.1
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    • pp.35-46
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    • 2015
  • Purpose: To present a flexible and accurate autonomous solution for creating any desired row spacing value between the hydroponic gullies in multilayer growing units, and evaluate the capabilities and performance of the relevant automated system through the use of virtual prototyping technique. Methods: To build the virtual prototype of the system, CAD models of its different parts, including an autonomous vehicle and the mechanical mechanisms embedded in the multilayer growing unit, were developed and imported into the RecurDyn simulation software. In order to implement the automated row spacing operation, three spacing modes with different loading cycles and working steps were defined, and the operation of the system was simulated to obtain the target row spacing values specified for each of these modes. Results: Motion profiles related to the horizontal displacement of: 1) the lower and upper sliding bars installed in the cultivation layers, and 2) the hydroponic gullies, during the simulation of the system operation, were generated and analyzed. No deviation from the specified target spacing values was observed at the end of simulations for all spacing modes. Conclusions: The results of the motion analysis obtained by simulating the system operation confirm the effectiveness of the control scheme proposed for automated row spacing of gullies. It was also found that proper sequencing of the loading cycles and the precision of the working strokes of the upper bars are the critical factors for establishing a certain row spacing value. Based on the simulation results, precise control of the back and forth motions of the upper bars is highly necessary for sound operation of the real system.

Numerical Model Applicability Based on a Hydraulic Characteristic Analysis of an Eco-friendly Double-row Submerged Breakwater

  • Yeon-Myeong Jeong;Jaeheon Jeong;Taegun Park;Ho-Seong Jeon;Dong-Soo Hur
    • Journal of Ocean Engineering and Technology
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    • v.38 no.4
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    • pp.164-173
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    • 2024
  • In this study, a submerged breakwater with effective wave control and eco-friendly characteristics is developed and proposed. Hydraulic experiments are conducted to compare the hydraulic performance of a submerged breakwater and an eco-friendly double-row submerged breakwater. The hydraulic characteristics are analyzed based on wave reflections and the transmission-splitting method for each experimental cross-section. This splitting technique utilizes Goda's two-point method, which employs the spectra of two irregular superposed wave fields. In addition, the reliability of the results obtained from the hydraulic experiments is discussed by comparing the results with empirical formulas. The eco-friendly double-row submerged breakwater features approximately half the width of a typical submerged breakwater. Nevertheless, its transmission coefficient (KT) is approximately 20% more effective, and the difference in the average reflection coefficient (KR) values between the two is approximately 0.17. Moreover, the dissipation coefficient (KD) shows a generally similar trend. Based on these experimental results, the hydraulic performance of the eco-friendly double-row submerged breakwater is more efficient regarding wave control, compared with a typical submerged breakwater. These hydraulic characteristics confirm that the numerical model developed for the eco-friendly double-row submerged breakwater accurately reproduces the KT, KR, and KD values within ±5%.

A Design Method of Earth-Retaining Structure Constructed by a Row of Bored Piles in Cohesive Soils (점성토지반속 주열식 흙막이벽의 설계법)

  • Hong, Won-Pyo;Gwon, U-Yong;Go, Jeong-Sang
    • Geotechnical Engineering
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    • v.5 no.3
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    • pp.29-38
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    • 1989
  • A design method is presented for the earth-retaining structure ccnslructtd by a row of bored Piles, which has such merits as low-vibration and low-noire during construction. And utility of the design method is investigated by performing a design example. First, theoretical rquations to estimate the resisting force of a row of earth-retaining was in cohesive soils are estabilished for grounds above and below bottom of excavation, reprctively. The characteristics of soils and the effect pile's interval can be considered logically in the theoretical equations. Then, the method for stability.analysis is presented for the earth-retaining piles by applying the theoretical equation of resisting forces on a row of piles. Finally, the design of earth-retaining piles is performed within the ranges which can satisfy the stabilities of both piles and soils. On investigation cf the sail-stability, the stability for bottom heave In cohesive soils is also investigated.

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Effect of Harvesting System on Labor-saving in Sweetpotato Cultivation (고구마 수확작업체계별 생력효과의 차이)

  • Kim, Hag-Sin;Lee, Joon-Seol;Chung, Mi-Nam
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.56 no.4
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    • pp.400-403
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    • 2011
  • This experiment was carried out to determine the effect of mechanization on lavor-saving in sweetpotato cultivation. The field experiment was conducted from 2005 to 2006 in Mokpo Experiment Station of the National Institute of Crop Science. In order to determine the efficiency of mechanical harvesting, different harvesting methods were compared. Mechanical harvesting method was done as follows: cutting of vines by machine, removal of plastic film mulching, and harvesting by two-row and one-row harvesting system. The result showed harvesting labor was decreased by 66.6% in two-row harvesting. The ratio of damaged sweetpotato by mechanical harvesting decreased by 49.4% in two-row and 38.4% in one-row harvesting compared to conventional method. The total labor cost was saved by 48.2% - 70.4% using mechanical method. In addition, the total income also increased by ca. 62.9% - 81.2%. Thus, it was concluded that mechanical harvesting is more efficient and economical method than conventional one.

An Experimental Study on the Dynamic Coefficients according to the Source Positions in Externally Pressurised Air-lubricated Journal Bearing with Two Row Sources (2열 외부가압 공기 저어널 베어링에서 급기구 위치에 따른 동적계수에 관한 실험적 연구)

  • 이종렬;이준석;이득우;김태형;박보선
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2001.10a
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    • pp.243-249
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    • 2001
  • This paper has been presented the hydrodynamic effect by the journal speed, eccentricity and source positions in order to overcome the defects of air bearing such as low stiffness and damping coefficient. Choosing the two row source position of air bearing is different from existed investigations in the side of pressure distribution of air film because of the high speed of journal and the wedge effects by the eccentricity. These optimal chooses of the two row source positions enable us to improve the performance of the film reaction force and loading force as making the high speed spindle. In this paper, the pressure behavior in theory of air film according to the eccentricity of journal and the source positions analyzed. The theoretical analysis have been identified by experiments. The results of investigated characteristics may be applied to precision devices like ultra-precision grinding machine and ultra high speed milling.

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Two-Phase Genetic Algorithm for Solving the Paired Single Row Facility Layout Problem

  • Parwananta, Hutama;Maghfiroh, Meilinda F.N.;Yu, Vincent F.
    • Industrial Engineering and Management Systems
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    • v.12 no.3
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    • pp.181-189
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    • 2013
  • This paper proposes a two-phase genetic algorithm (GA) to solve the problem of obtaining an optimum configuration of a paired single row assembly line. We pair two single-row assembly lines due to the shared usage of several workstations, thus obtaining an optimum configuration by considering the material flow of the two rows simultaneously. The problem deals with assigning workstations to a sequence and selecting the best arrangement by looking at the length and width for each workstation. This can be considered as an enhancement of the single row facility layout problem (SRFLP), or the so-called paired SRFLP (PSRFLP). The objective of this PSRFLP is to find an optimal configuration that seeks to minimize the distance traveled by the material handler and even the use of the material handler itself if this is possible. Real-world applications of such a problem can be found for apparel, shoe, and other manual assembly lines. This research produces the schematic representation solution using the heuristic approach. The crossover and mutation will be utilized using the schematic representation solution to obtain the neighborhood solutions. The first phase of the GA result is recorded to get the best pair. Based on these best matched pairs, the second-phase GA can commence.

A Study on the Response Characteristics of Fire Detector by Full-scale Experiment of Fire Phenomena in the Row House (주택 실물화재실험에 의한 화재감지기 응답특성에 관한 연구)

  • SaKong, Seong-Ho;Kim, Shi-Kuk;Lee, Chun-Ha;Jung, Jong-Jin
    • Fire Science and Engineering
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    • v.23 no.3
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    • pp.67-72
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    • 2009
  • This paper is for response feature of fire detectors not only to analysis response feature of fire detector, but also to observe flame spread of inside-building and fire enlargement by using the row house which is supposed to be broken up. Many kinds of popular detectors such as heat type detector(differential type, fixed temperature type, Analogue type)and smoke type(light scattered type, Analogue type, single alarm type) were installed in the house in order to check for the change of temperature by installing of thermocouples. As a result, smoke detectors are better than heat detectors when it comes to making effective fire-detect system in the row house.

Studies on the Leaf Characteristics and the Photosynthesis of Korean Ginseng II. Seasonal Changes of Photosynthesis of 4-Year Old Ginseng(Panax ginseng C.A. Meyer) (고려인삼엽의 광합성능력에 관한 연구 II. 4년생 인삼의 광합성의 계절 변이)

  • 조재성;목성균;원준연
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.30 no.4
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    • pp.398-404
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    • 1985
  • This study was conducted to define the seasonal differences in the morphological characteristics, the photosynthetic abilities and the dark respirations of the 4-year old ginseng leaves. Chlorophyll-a content in the ginseng leaf was significantly decreased at September than at June but content of chlorophyll-b was not showed seasonal difference. At June, the amounts of chlorophyll a and b in the ginseng leaves grown in the back row were rather abundant than those grown in the front row, but no significant differencies were detected between rows at September. The estimated optimum light intensity for the photosynthesis of ginseng leaves was higher at June than at September and higher in the front row than the back row but was significantly decreased by air temperature above 25$^{\circ}C$. The light compensation point was elevated in higher temperature and at September than June. The amount of photosynthesis was significantly increased in the ginseng plant grown in the front row than the back row at June but the reverse was significant at September. The highest photosynthesis was observed in temperature range of 20 - 25$^{\circ}C$ at June and range of 15 -20$^{\circ}C$ at September. The optimum temperature range of photosynthesis was 21$^{\circ}C$ to 25$^{\circ}C$ at June and 14$^{\circ}C$ to 21$^{\circ}C$ at September, and that was higher in the back row than the front row. High temperature significantly stimulated the dark respiration of ginseng leaves and the respiratory quotients(Q$\_$10/) of the ginseng leaves showed a significant seasonal variation.

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Evaluation of Maize Downy Mildew using Spreader Row Technique (Spreader Row Technique을 이용한 옥수수 노균병 검정)

  • Kim, Kyung-Hee;Moon, Jun-Cheol;Kim, Jae Yoon;Kim, Hyo Chul;Shin, Seungho;Song, Kitae;Baek, Seong-Bum;Lee, Byung-Moo
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.61 no.1
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    • pp.41-49
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    • 2016
  • This study was conducted to evaluate maize downy mildew resistance using spreader row technique in Cambodia. A total of forty maize lines were used in this experiment. Seven Korean varieties and seven breeding lines showed high infection rates (80~100%) and highly susceptible (HS) to downy mildew disease in both spring and fall. Also most of nested association mapping (NAM) parent lines were highly susceptible (HS). Meanwhile three inbred lines, Ki3, Ki11, and CML228, showed highly resistant (HR) or resistant (R) in spring and moderately resistant (MR) in fall. These three lines were already known as resistant inbred lines against downy mildew disease. It appears that spreader row technique was suitable for selection of maize downy mildew resistance in Cambodia. The incidence of downy mildew was influenced by weather conditions, especially relative humidity and temperature. Among several inoculation methods to screen for downy mildew resistance, this spreader row technique is effectively and easily used in the field of Southeast Asia.

Cooling characteristics of the multichip module using paraffin slurry (파라핀 슬러리를 사용한 다칩모듈의 냉각특성)

  • Jo, Geum-Nam;Choe, Min-Gu
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.22 no.6
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    • pp.888-898
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    • 1998
  • The present study investigated the effects of the experimental parameters on the cooling characteristics of the multichip module cooled by the indirect liquid cooling method using water and paraffin slurry. The experimental parameters are mass fraction of 2.5 ~ 7.5% for paraffin slurry, heat flux of 10 ~ 40 W/cm$^{2}$ for the simulated VLSI chips and Reynolds numbers of 5,300 ~ 15,900. The apparatus consisted of test section, paraffin slurry maker, pump, constant temperature baths, flowmeter, etc. The test section made of in-line, four-row array of 12 heat sources for simulating 4 * 3 multichip module which was flush mounted on the top wall of a horizontal rectangular channel with the aspect ratio of 0.2. The inlet temperature was 20 deg. C for all experiments. The size of paraffin slurry was constant as 10 ~ 40 .mu.m befor and after the experiment. The chip surface temperatures for paraffin slurry with the mass fraction of 7.5% showed lower by 16 deg. C than those for water when the heat flux is 40 W/cm$^{2}$. The local heat transfer coefficients for the paraffin slurry with the mass fraction of 7.5% were larger by 17 ~ 25% than those for water at the first and the fourth row. The local heat transfer coefficients reached to a row-number-independent, thermally fully developed value approximately after the third row. The local Nusselt numbers at the fourth row for paraffin slurry with the mass fraction of 7.5% were larger by 23 ~ 29% than those for water.