Fukushima Technology Centre (Japan)

This paper presents the integration of a four-stage power command control system with an inverter-based power generation system (IBPGS) and its associated controller. A fifteenth-order small-signal state-space model has been developed to represent the dynamic behaviors of the IBPGS and its control architecture. To evaluate system robustness, variations in LCL filter parameters and grid impedance, both of which fluctuate during operation, have been systematically analyzed to determine their critical thresholds beyond which system instability may occur. The impact of weak and strong grid conditions on the stability of the IBPGS has been investigated. Eigenvalue trajectory analysis with root locus has been used to assess the stability limit of the IBPGS. The results of the analysis highlight the important role of LCL filter characteristics and grid impedance in governing the stability of inverter-based power systems.

Direct seeding of rice is increasingly used to grow the most suitable cultivars under the best cropping schedule in the face of changing climatic and weather conditions. Although crop modeling can be used to optimize these factors, models developed for transplanted rice are not directly applicable, owing to differences in crop development due to weather conditions. Here, we present a method for estimating a parameter set for a crop development model applicable to direct-seeded rice from a set developed for transplanted rice. We hypothesized that model parameters C and D, which are related to the initial development index, can describe the difference in crop development between direct seeding and transplanting. The method estimates the values of C and D for each practice independently using shared parameters A, Th, and G, which are related to the temperature response of development and the days required for panicle initiation and heading in transplanted rice. We used data from field trials conducted in Iwate Prefecture between 2015 and 2019 with ‘Ginga no Shizuku’ to establish and verify the method. The estimated parameter set was accurate within a root mean square error (RMSE) range of 1.08 to 3.85 days at the heading stage and 2.96 to 3.11 days at the panicle initiation stage. When we tested the validity of the method by growing ‘Ten no Tsubu’ in both practices, the estimated parameter accuracy was 2.06 to 3.37 days RMSE at heading. We conclude that our method supplies a suitable parameter set for crop development models of direct-sown rice with an acceptable degree of accuracy. It will contribute to the estimation of optimal combinations of cultivars and cropping schedules for direct-sown rice under climate change, using historical field trial data and estimated parameter sets for transplanted rice.

稲作における営農面積の拡大や温暖化環境に対応した省力化技術に資するため，近年，機械化が実用可能になった疎播苗の特性とその温度応答について東北地域の主要銘柄品種を用いて調査した．試験1では岩手大学において「あきたこまち」を3月下旬から6月中旬にかけて5回に分けて播種を繰り返し，疎播（乾籾60 g 箱—1），標準（同120 g箱—1），密播（同240 g箱—1）の3条件で育苗した稚苗および中苗の苗質を調査した．疎播苗は積算地温の上昇に伴う葉齢進展や地上部および根乾物重の増加が標準や密播よりも大きかった．また，疎播苗は草丈あたりの乾物重が大きく，他の播種密度よりも高い苗充実度を示した．試験2の東北地域の主要銘柄品種における疎播苗 （同65～80 g箱—1） と慣行苗 （同120～160 g箱—1） の比較においても，疎播苗は栽培地や品種に関わらず，積算気温が400～700℃日の範囲において慣行苗よりも高い乾物重と苗充実度を示した．いずれの試験においても疎播苗は温度1℃あたりの乾物生産量が他の播種密度よりも大きく，このことが幅広い温度域における優れた乾物生産能や苗充実度に寄与していた．したがって，春の異常昇温や大規模経営体での移植作業の遅れに伴う育苗期間の延長など，育苗時の温度環境が上昇した場合でも疎播苗は優れた苗質を維持できることから，移植時期が長期となる大規模経営体や温暖化環境に適応した技術であると考えられる．

BackgroundPostoperative shoulder stiffness (POSS) is one of the most common complications of arthroscopic rotator cuff repair (ARCR). Although adduction restriction is commonly observed in the early postoperative period, it remains unclear whether a prolonged duration of this restriction impacts the development of POSS. The aim of this study was to investigate whether early postoperative adduction restriction is associated with the occurrence of POSS 1 year after ARCR.MethodsThis retrospective cohort study included patients who underwent ARCR at a single institution between April 2017 and June 2018. A total of 96 shoulders were analyzed. Active and passive range of motion were assessed preoperatively and at 12 months postoperatively. Adduction restriction was evaluated in two positions: the droop position and the intermediate position. Adduction restriction was defined as resolved when the medial side of the arm made contact with the side of the body. Based on these evaluations, the duration of persistent postoperative adduction restriction was evaluated. POSS was defined as passive external rotation at the side of less than 30° at 12 months after surgery according to the previous studies. Patients were assigned to one of two groups: Group N, without POSS group, or Group S, with POSS group. Propensity score matching was used to ensure comparability between groups. The duration of persistent postoperative adduction restriction was compared between the groups.ResultsAfter propensity score matching, 38 shoulders were analyzed (19 in Group N and 19 in Group S). While no significant difference in the duration of persistent postoperative adduction restriction in the droop position between the groups was observed, the duration in the intermediate position was significantly shorter in Group N compared to Group S (7 ± 3 weeks vs. 10 ± 4 weeks, P = .007).ConclusionThe duration of persistent adduction restriction in the intermediate position was significantly longer in shoulders with POSS at 12 months after ARCR compared to those without POSS. Prolonged early postoperative adduction restriction may associate with the occurrence of POSS 12 months after ARCR.

交換性カリウム濃度がイネの放射性セシウム吸収に影響を与えない程度に高い条件では、玄米の放射性セシウム濃度は，土壌中の溶存態放射性セシウム量から精度よく予測できる。しかし，溶存態放射性セシウム量の実測には，大量の土壌溶液採取やろ過・濃縮等の多大な労力が必要である。そこで，亜鉛置換型プルシアンブルーを担持した吸着シートで土壌中の溶存態放射性セシウムを吸着し，シートに吸着した溶存態放射性セシウム量から玄米放射性セシウム濃度を簡易に予測することが可能か否かを検討した。表面をメンブランフィルターで被覆することにより土壌粒子の付着を防ぐ加工をしたセシウム吸着ディスクを現地水田の作土に2週間埋設し，溶存態放射性セシウムを回収した。吸着シートに回収された放射性セシウム量は，玄米放射性セシウム濃度と高い正の相関があった。分げつ期に吸着シートを埋設し，回収された放射性セシウム濃度を分析することで，大量の土壌溶液の採取や土壌理化学性の分析を必要とせず，玄米中放射性セシウム濃度を予測出来る可能性が示された。

We collected 3180 records of oleic acid (C18:1) and monounsaturated fatty acid (MUFA) measured using gas chromatography (GC) and 6960 records of C18:1 and MUFA measured using near-infrared spectroscopy (NIRS) in intermuscular fat samples of Japanese Black cattle. We compared genomic prediction performance for four linear models (genomic best linear unbiased prediction [GBLUP], kinship-adjusted multiple loci [KAML], BayesC, and BayesLASSO) and five machine learning models (Gaussian kernel [GK], deep kernel [DK], random forest [RF], extreme gradient boost [XGB], and convolutional neural network [CNN]). For GC-based C18:1 and MUFA, KAML showed the highest accuracies, followed by BayesC, XGB, DK, GK, and BayesLASSO, with more than 6% gain of accuracy by KAML over GBLUP. Meanwhile, DK had the highest prediction accuracy for NIRS-based C18:1 and MUFA, but the difference in accuracies between DK and KAML was slight. For all traits, accuracies of RF and CNN were lower than those of GBLUP. The KAML extends GBLUP methods, of which marker effects are weighted, and involves only additive genetic effects; whereas machine learning methods capture non-additive genetic effects. Thus, KAML is the most suitable method for breeding of fatty acid composition in Japanese Black cattle.

Farmland in the Fukushima region of Japan experienced serious radioactive contamination as a result of the Fukushima Nuclear Power Plant disaster in 2011. A large number of farm-fields have been decontaminated by replacing the top surface soil with non-contaminated soil. This preliminary study investigated the potential of high spatial- and temporal-resolution micro-satellite Venμs and ground-based hyperspectral sensing techniques for assessment of soil fertility and rice productivity in the region to assist the agricultural recovery. Results suggested that these variables would be estimated in a regional scale by remote sensing approaches.