Twenty years of the history of the International Society of Paddy and Water Environment Engineering (PAWEES) are reviewed, focusing on a retrospective review and discussion of issues from the ...seven-year period from 2000 to 2006, including the preparatory period leading up to its establishment. PAWEES was established on January 1, 2003 in collaboration with three related societies in Japan, Korea, and Taiwan, triggered by the need for the training of engineers in paddy field agricultural engineering and to obtain the international recognition of such a discipline for the international accreditation of engineering education programs. Since its inception, PAWEES has become a substantial international society through the continuous publication of an international journal, international conferences, and research meetings. For its future development, it is crucial to expand the network to focus on countries and regions with paddy farming and to develop human resources with an international outlook. This paper is based on authors’ personal information obtained through their participation in various activities concerning PAWEES and the publication of the journal Paddy and Water Environment (PAWE).
In this study, we aimed to develop and assess a hydrological model using a deep learning algorithm for improved water management. Single-output long short-term memory (LSTM SO) and encoder-decoder ...long short-term memory (LSTM ED) models were developed, and their performances were compared using different input variables. We used water-level and rainfall data from 2018 to 2020 in the Takayama Reservoir (Nara Prefecture, Japan) to train, test, and assess both models. The root-mean-squared error and Nash–Sutcliffe efficiency were estimated to compare the model performances. The results showed that the LSTM ED model had better accuracy. Analysis of water levels and water-level changes presented better results than the analysis of water levels. However, the accuracy of the model was significantly lower when predicting water levels outside the range of the training datasets. Within this range, the developed model could be used for water management to reduce the risk of downstream flooding, while ensuring sufficient water storage for irrigation, because of its ability to determine an appropriate amount of water for release from the reservoir before rainfall events.
Assurance cases are documents for arguing that systems satisfy required properties such as safety and security in the given environment based on sufficient evidence. As systems become complex and ...networked, the importance of assurance cases has become significant. However, we observe that creating assurance cases has some essential difficulties, and unfortunately it seems that assurance cases have not been widely used in industries. For this problem, we have been developing assurance cases creation methods and opening workshops based on the creation methods. This paper presents an assurance cases creation method called “D-Case Steps” which is based on d* framework1, an agent-based assurance case method, and reports the results of workshops. The results indicate that our workshops have been improved and our activities on assurance cases facilitates use of them in Japan. This paper is an extended version of 2. We add detailed background and related works, workshops results and evaluation, and lessons learned from our a decade experiences.
In recent years, Paddy Field Dams have received recognition as a measure to alleviate flooding due to torrential rains. Paddy Field Dams have been in practice in several prefectures of Japan, namely ...Niigata, Hyogo, and Nara Prefectures. Various issues have come to attention when introducing Paddy Field Dams to rural communities, such as the discrepancy in valuation between beneficiaries (downstream communities of paddy fields) and practitioners (farmers and irrigation administrators), the framework for supporting farmers in their installation, operation and maintenance, and identification of strategic locations in the context of river basin management. The purpose of this study was to clarify perceptions and valuations of Paddy Field Dam functions by rural communities in Nara Prefecture, Japan, under the above-mentioned issues. Analysis was performed using the results of a questionnaire survey conducted in three districts of Nara Prefecture. In addition, a Contingent Valuation Method (CVM) was applied to estimate the economic value of a Paddy Field Dam. The results indicated that awareness of Paddy Field Dams was lower than expected. However, it was found that many respondents value their practice and expect them to reduce the risk of flood damage effectively. In addition, the results of the CVM analysis showed that the annual willingness to pay (WTP) per household was estimated at a median value of 2200 yen to 3000 yen, with an average value of 3600 yen to 5600 yen. The WTP tended to be higher for districts that had experienced flooding in the past.
Japanese agriculture is facing a decrease in agricultural workers. Mechanization, both to save time and reduce physical input, is essential to solving this issue. Recent worldwide progress in ...Internet-of-things technology has enabled the application of remote-controlled and unmanned machinery in agriculture. This study was conducted in the Gojo-Yoshino mountainous region in Nara, Japan, which is famous for its persimmon cultivation. The performance of newly introduced smart agricultural machinery was studied in the field by simulating cultivation work. The results showed that the remote-control weeder, speed sprayer, and remote-control mini crawler carrier saved 90%, 75%, and 5% of weeding, spraying, and harvesting times, respectively, when compared with conventional methods. Such time savings led to an 8% decrease in the total working time spent on persimmon cultivation. In addition, using the speed sprayer showed improvement in the fruit’s quality. Results of the power assist suits did not show a time-saving effect but showed a reduction of physical burden. These results suggest that the mechanization of persimmon cultivation is efficient and labor-saving, and satisfies the need for farmers. However, the high investment costs remain an issue in extending mechanization to the region.
Assurance cases are documented body of evidence that provide valid and convincing argument that the system is adequately dependable in a given application and an environment. Assurance cases are ...widely required as a regulation for safety-critical systems in EU. There have been several graphical notations for assurance cases. GSN (Goal Structuring Notation) and CAE (Claim, Argument, Evidence) are such two notations. However, these notations have not been defined in a formal way. This paper presents a formal definition of GSN and its pattern extensions. We take the framework of functional programming language as the basis of our study. The implementation has been done on an Eclipse based GSN editor. We report case studies on previous works about GSN and show the applicability of the design and implementation. This is a step toward developing an assurance case language.
Actual crop evapotranspiration (ET) and crop coefficient (Kc) of ratoon rice crop, which are necessary for irrigation planning, have been hardly reported. ET can be directly measured by lysimeter and ...eddy covariance but it is expensive, so it remains difficult to determine ET, especially in developing countries. The focus of this study was to evaluate the ET and Kc of ratoon cropping in a tropical region of Myanmar using a simplified method. Our method combined the manual observation of water depth in concrete paddy tanks and the ET model estimation using Bayesian parameter inference. The ET and Kc could be determined using this method with an incomplete observation dataset. The total ET of ratoon was 60–70% less than that of the main crop, but this difference was mainly attributed to climate conditions in each cultivation. The Kc regression curve between transplanted rice and ratoon crops was different because of the tillering traits. The results suggest that irrigation scheduling of ratoon cropping in the initial growth stage should take high crop water requirements into account. In addition, the productivity of ratoon crop is equivalent to transplanted rice, which was determined for cultivation in experiment conditions of small concrete tanks. Therefore, further study on ratoon in Myanmar is necessary for clarifying the viability of ratoon cropping.
Graphene and graphene oxide (GO) in solution were directly observed by a newly developed twilight fluorescence (TwiF) microscopy. A nanocarbon dispersion was mixed with a highly concentrated ...fluorescent dye solution and placed in a cell with a viewing glass at the bottom. TwiF microscopy images the nanocarbon material floating within a few hundred μm of the glass surface by utilizing two optical processes to provide a faintly illuminating backlight and visualizes GO as either a dark image by absorption and energy transfer processes or a bright image by alternation of fluorophore chemistry and autofluorescence. Individual graphene and GO sheets ranging from submicron to submillimeter widths were clearly imaged at different wavelengths, which were selectable based on the dye used. Graphene could be differentiated from GO coexisting in the same solution. Partial transparency revealed layering and network structures. Motions in tumbling flow were recognized in real time. An effect of changing the solvent and the process of adhesion on the glass surface were followed in situ.
The two-layer Shuttleworth–Wallace (SW) evapotranspiration (ET) model has been widely used for predicting ET with good results. Since the SW model has a large number of specific parameters, these ...parameters have been estimated using a simple non-hierarchical Bayesian (SB) approach. To further improve the performance of the SW model, we aimed to assess parameter estimation using a two-level hierarchical Bayesian (HB) approach that takes into account the variation in observed conditions through the comparison with a traditional one-layer Penman–Monteith (PM) model. The difference between the SB and HB approaches were evaluated using a field-based ET dataset collected from five agricultural fields over three seasons in Myanmar. For a calibration period with large variation in environmental factors, the models with parameters calibrated by the HB approach showed better fitting to observed ET than that with parameters estimated using the SB approach, indicating the potential importance of accounting for seasonal fluctuations and variation in crop growth stages. The validation of parameter estimation showed that the ET estimation of the SW model with calibrated parameters was superior to that of the PM model, and the SW model provided acceptable estimations of ET, with little difference between the SB and HB approaches.
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