• Title/Summary/Keyword: Impact-resistance

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Home Economics Teachers' Concern and Perception about Home Economics Education Using the Latest Technology in the Era of the 4th Industrial Revolution (4차 산업혁명 시대의 최신 기술을 활용한 가정과교육에 대한 가정과교사의 관심과 인식)

  • Eui Jung Kim;Won Joon Lee;Do Ha Jeong;Sung Mi Cho;Jung Hyun Chae
    • Human Ecology Research
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    • v.61 no.4
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    • pp.673-686
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    • 2023
  • The purpose of this study was to identify home economics (HE) teachers' concerns about and perceptions of HE education using the latest technologies in the era of the 4th Industrial Revolution and to reveal whether they differ according to teachers' general background variables. The questionnaire survey method to measure HE teachers' concerns and perceptions of HE education using the latest technologies in the era of the 4th Industrial Revolution was conducted online using the Google Questionnaire from which 150 responses were received. The main results were as follows. Firstly, HE teachers scored an average of 3.46 out of 5 for the latest technology. Among these interests in the latest technology, interest in "augmented reality and virtual reality technologies" scored the highest at an average of 3.80, while interest in "neural network machine learning" (2.78) was low. HE teacher's concerns about HE education using the latest technologies in the era of the 4th Industrial Revolution were high, with an average score of 4.40. Among these concerns for the latest technology, "concern about the results of HE education using the latest technology" scored the highest at 4.53. HE teachers' anxiety about the latest teaching technology in the era of the 4th Industrial Revolution was moderate, averaging 3.05. The highest form of anxiety was "anxiety about the impact on the job" (4.03) and the lowest was fear of "the disappearance of the teacher's job" (2.50). HE teachers' innovation resistance to the latest teaching technology was low at 2.18. Expectations of the latest technology in HE classes in the era of the 4th Industrial Revolution averaged 3.85, slightly higher than the middle of 3.

Three-Dimensional Printing of Congenital Heart Disease Models for Cardiac Surgery Simulation: Evaluation of Surgical Skill Improvement among Inexperienced Cardiothoracic Surgeons

  • Ju Gang Nam;Whal Lee;Baren Jeong;Eun-Ah Park;Ji Yeon Lim;Yujin Kwak;Hong-Gook Lim
    • Korean Journal of Radiology
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    • v.22 no.5
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    • pp.706-713
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    • 2021
  • Objective: To evaluate the impact of surgical simulation training using a three-dimensional (3D)-printed model of tetralogy of Fallot (TOF) on surgical skill development. Materials and Methods: A life-size congenital heart disease model was printed using a Stratasys Object500 Connex2 printer from preoperative electrocardiography-gated CT scans of a 6-month-old patient with TOF with complex pulmonary stenosis. Eleven cardiothoracic surgeons independently evaluated the suitability of four 3D-printed models using composite Tango 27, 40, 50, and 60 in terms of palpation, resistance, extensibility, gap, cut-through ability, and reusability of. Among these, Tango 27 was selected as the final model. Six attendees (two junior cardiothoracic surgery residents, two senior residents, and two clinical fellows) independently performed simulation surgeries three times each. Surgical proficiency was evaluated by an experienced cardiothoracic surgeon on a 1-10 scale for each of the 10 surgical procedures. The times required for each surgical procedure were also measured. Results: In the simulation surgeries, six surgeons required a median of 34.4 (range 32.5-43.5) and 21.4 (17.9-192.7) minutes to apply the ventricular septal defect (VSD) and right ventricular outflow tract (RVOT) patches, respectively, on their first simulation surgery. These times had significantly reduced to 17.3 (16.2-29.5) and 13.6 (10.3-30.0) minutes, respectively, in the third simulation surgery (p = 0.03 and p = 0.01, respectively). The decreases in the median patch appliance time among the six surgeons were 16.2 (range 13.6-17.7) and 8.0 (1.8-170.3) minutes for the VSD and RVOT patches, respectively. Summing the scores for the 10 procedures showed that the attendees scored an average of 28.58 ± 7.89 points on the first simulation surgery and improved their average score to 67.33 ± 15.10 on the third simulation surgery (p = 0.008). Conclusion: Inexperienced cardiothoracic surgeons improved their performance in terms of surgical proficiency and operation time during the experience of three simulation surgeries using a 3D-printed TOF model using Tango 27 composite.

Influence of Ga Content on the Ionic Conductivity of Li1+XGaXTi2-X(PO4)3 Solid-State Electrolyte Synthesized by the Sol-Gel Method

  • Seong-Jin Cho;Jeong-Hwan Song
    • Korean Journal of Materials Research
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    • v.34 no.4
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    • pp.185-193
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    • 2024
  • In this study, NASICON-type Li1+XGaXTi2-X(PO4)3 (x = 0.1, 0.3 and 0.4) solid-state electrolytes for all-solid-state batteries were synthesized through the sol-gel method. In addition, the influence on the ion conductivity of solid-state electrolytes when partially substituted for Ti4+ (0.61Å) site to Ga3+ (0.62Å) of trivalent cations was investigated. The obtained precursor was heat treated at 450 ℃, and a single crystalline phase of Li1+XGaXTi2-X(PO4)3 systems was obtained at a calcination temperature above 650 ℃. Additionally, the calcinated powders were pelletized and sintered at temperatures from 800 ℃ to 1,000 ℃ at 100 ℃ intervals. The synthesized powder and sintered bodies of Li1+XGaXTi2-X(PO4)3 were characterized using TG-DTA, XRD, XPS and FE-SEM. The ionic conduction properties as solid-state electrolytes were investigated by AC impedance. As a result, Li1+XGaXTi2-X(PO4)3 was successfully produced in all cases. However, a GaPO4 impurity was formed due to the high sintering temperatures and high Ga content. The crystallinity of Li1+XGaXTi2-X(PO4)3 increased with the sintering temperature as evidenced by FE-SEM observations, which demonstrated that the edges of the larger cube-shaped grains become sharper with increases in the sintering temperature. In samples with high sintering temperatures at 1,000 ℃ and high Ga content above 0.3, coarsening of grains occurred. This resulted in the formation of many grain boundaries, leading to low sinterability. These two factors, the impurity and grain boundary, have an enormous impact on the properties of Li1+XGaXTi2-X(PO4)3. The Li1.3Ga0.3Ti1.7(PO4)3 pellet sintered at 900 ℃ was denser than those sintered at other conditions, showing the highest total ion conductivity of 7.66 × 10-5 S/cm at room temperature. The total activation energy of Li-ion transport for the Li1.3Ga0.3Ti1.7(PO4)3 solid-state electrolyte was estimated to be as low as 0.36 eV. Although the Li1+XGaXTi2-X(PO4)3 sintered at 1,000 ℃ had a relatively high apparent density, it had less total ionic conductivity due to an increase in the grain-boundary resistance with coarse grains.

Korean Society of Heart Failure Guidelines for the Management of Heart Failure: Management of the Underlying Etiologies and Comorbidities of Heart Failure

  • Sang Min Park;Soo Youn Lee;Mi-Hyang Jung;Jong-Chan Youn;Darae Kim;Jae Yeong Cho;Dong-Hyuk Cho;Junho Hyun;Hyun-Jai Cho;Seong-Mi Park;Jin-Oh Choi;Wook-Jin Chung;Seok-Min Kang;Byung-Su Yoo;Committee of Clinical Practice Guidelines, Korean Society of Heart Failure
    • Korean Circulation Journal
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    • v.53 no.7
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    • pp.425-451
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    • 2023
  • Most patients with heart failure (HF) have multiple comorbidities, which impact their quality of life, aggravate HF, and increase mortality. Cardiovascular comorbidities include systemic and pulmonary hypertension, ischemic and valvular heart diseases, and atrial fibrillation. Non-cardiovascular comorbidities include diabetes mellitus (DM), chronic kidney and pulmonary diseases, iron deficiency and anemia, and sleep apnea. In patients with HF with hypertension and left ventricular hypertrophy, renin-angiotensin system inhibitors combined with calcium channel blockers and/or diuretics is an effective treatment regimen. Measurement of pulmonary vascular resistance via right heart catheterization is recommended for patients with HF considered suitable for implantation of mechanical circulatory support devices or as heart transplantation candidates. Coronary angiography remains the gold standard for the diagnosis and reperfusion in patients with HF and angina pectoris refractory to antianginal medications. In patients with HF and atrial fibrillation, longterm anticoagulants are recommended according to the CHA2DS2-VASc scores. Valvular heart diseases should be treated medically and/or surgically. In patients with HF and DM, metformin is relatively safer; thiazolidinediones cause fluid retention and should be avoided in patients with HF and dyspnea. In renal insufficiency, both volume status and cardiac performance are important for therapy guidance. In patients with HF and pulmonary disease, beta-blockers are underused, which may be related to increased mortality. In patients with HF and anemia, iron supplementation can help improve symptoms. In obstructive sleep apnea, continuous positive airway pressure therapy helps avoid severe nocturnal hypoxia. Appropriate management of comorbidities is important for improving clinical outcomes in patients with HF.

Christian Religious Education's Enchanting Duty : A Curriculum of Hope from the Underside of Civic Polarization, Moral Disimagination, and Learned Helplessness (책임을 노래하는 기독교적 종교교육 : 시민적 양극성, 도덕적 무감각, 학습된 무력감의 저변에서 시작된 희망의 교육과정)

  • Le Tran Mai Anh
    • Journal of Christian Education in Korea
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    • v.77
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    • pp.7-27
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    • 2024
  • This study addresses the crucial role of Christian Religious Education (CRE) amidst civic polarization, moral disimagination, and learned helplessness. It begins her personal background as a 1.5-generation Vietnamese American and her academic engagement in immigrant faith and the challenges of teaching faith in violent contexts. The work underscores the public dimension and impact of religious education, highlighting its potential for fostering critical capacities for public engagement. However, that study observes a prevalent disconnection between congregational culture and the aim of public engagement, leading to a form of learned helplessness among students and communities. The researcher draws on Paulo Freire's concepts of "critical hope" and the need for a curriculum that transcends mere content delivery to foster transformative engagement with societal issues. The document critiques the disimigination machine that undermines critical thinking and collective resistance, as articulated by Henry Giroux, and explores the concepts of "learned helplessness" as a barrier to environmental and social activism. The researcher advocates for a theopoetic and theopolitical approach to education that nurtures hope and practical engagement with the world's injustice. She emphasizes small acts of theopoetic and theopolitical hope as transformative practices, using an example from Ferguson, Missouri, to illustrate how public liturgy and protest can mediate hope and justice. The document concludes with a call for a life-long, life-wide, and life-deep curriculum of enchantment towards responsible participation in societal repair, rooted in Christian hope.

Differences in Sleep Patterns are Related to Behavior, Emotional Problems, Attention and Academic Performance in Elementary School Students of a South Korean Metropolitan City (일 도시의 초등학교 학생의 수면습관과 행동, 정서, 주의력, 학습과의 관계)

  • Tak, Hee-Jong;Lee, Ji-Ho;Lee, Chang-Myung;Chung, Seok-Hoon;Lee, Jae-Won;Sim, Chang-Sun;Yoon, Jae-Goog;Sung, Joo-Hyeon;Bhang, Soo-Young
    • Journal of the Korean Academy of Child and Adolescent Psychiatry
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    • v.22 no.3
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    • pp.182-191
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    • 2011
  • Objectives: The aim of this study was to investigate the sleep patterns of South Korean elementary school children and whether the differences in sleep patterns were related to behavior, emotional problems, attention and academic performance. Method: This study included a community sample of 268 boys and girls from fourth-, fifth- and sixth-grade classes in a South Korean metropolitan city from November to December 2010. The primary caregivers completed a questionnaire that included information on demographic characteristics, as well as the Child's Sleep Habit Questionnaire (CSHQ), the Korean version of Child Behavior Checklist (K-CBCL), the Korean version of the Learning Disability Evaluation Scale (K-LDES), the Korean version of ADHD Rating Scale (K-ARS) and the Disruptive Behavior Disorder Scale (DBDS). We conducted analyses on the CSHQ individual items, between the subscales, on the total scores and on the K-CBCL, the K-LEDS, the K-ARS and the DBDS. Results: Based on the findings from the CHSQ, the subjects had significantly higher scores for bedtime resistance ($9.18{\pm}2.17$), delayed sleep onset ($1.32{\pm}0.62$), the sleep duration ($4.19{\pm}1.52$) and daytime sleepiness ($14.10{\pm}3.55$) than the scores from the previous reports on children from western countries. The total CHSQ score showed positive correlations to all subscales of the K-CBCL : withdrawn (r=0.24, p<.005), somatic complaint (r=0.24, p<.005) and anxious/depressive (r=0.38, p<.005). Bedtime resistance was associated with oppositional defiant disorder (r=0.15, p<.05) and a positive correlation was demonstrated between sleep anxiety and the oppositional defiant disorder score (r=0.13, p<.05), night waking and the conduct disorder score (r=0.16, p<.05). Delayed sleep onset was related with low performance on the K-LDES with respect to thinking (r=-0.17, p<.05) and mathematical calculation (r=-0.17, p<.05). Conclusion: The results of this study reconfirm Korean children's problematic sleep patterns. Taken together the results provide that the reduced sleep duration and disruption of sleep pattern can have a significant impact on emotion, behavior, performance of learning in children. Further studies concerning more diverse psychosocial factors affecting sleep pattern will be helpful to understanding of the sleep health in Korean children.

A New Detailed Assessment for Liquefaction Potential Based on the Liquefaction Driving Effect of the Real Earthquake Motion (실지진하중의 액상화 발생특성에 기초한 액상화 상세평가법)

  • 최재순;강한수;김수일
    • Journal of the Korean Geotechnical Society
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    • v.20 no.5
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    • pp.145-159
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    • 2004
  • The conventional method for assessment of liquefaction potential proposed by Seed and Idriss has been widely used in most countries because of simplicity of tests. Even though various data such as stress, strain, stress path, and excess pore water pressure can be obtained from the dynamic test, especially, two simple experimental data such as the maximum deviatoric stress and the number of cycles at liquefaction have been used in the conventional assessment. In this study, a new detailed assessment for liquefaction potential to reflect both characteristics of real earthquake motion and dynamic soil resistance is proposed and verified. In the assessment, the safety factor of the liquefaction potential at a given depth of a site can be obtained by the ratio of a resistible cumulative plastic shear strain determined through the performance of the conventional cyclic test and a driving cumulative plastic shear strain calculated from the shear strain time history through the ground response analysis. The last point to cumulate the driving plastic shear strain to initiate soil liquefaction is important for this assessment. From the result of cyclic triaxial test using real earthquake motions, it was concluded that liquefaction under the impact-type earthquake loads would initiate as soon as a peak loading signal was reached. The driving cumulative plastic shear strain, therefore, can be determined by adding all plastic shear strains obtained from the ground response analysis up to the peak point. Through the verification of the proposed assessment, it can be concluded that the proposed assessment for liquefaction potential can be a progressive method to reflect both characteristics of the unique soil resistance and earthquake parameters such as peak earthquake signal, significant duration time, earthquake loading type, and magnitude.

Impact of Pulmonary Vascular Compliance on the Duration of Pleural Effusion Duration after Extracardiac Fontan Procedure (수술 전 폐혈관 유순도가 심장 외 도판을 이용한 Fontan 수술 후 늑막 삼출 기간에 미치는 영향)

  • Yun Tae-Jin;Im Yu-Mi;Song Kwang-Jae;Jung Sung-Ho;Park Jeong-Jun;Seo Dong-Man;Lee Moo-Song
    • Journal of Chest Surgery
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    • v.39 no.8 s.265
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    • pp.579-587
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    • 2006
  • Background: Preoperative risk analysis for Fontan candidates is still less than optimal in that patients with apparently low risks may have poor surgical outcome; prolonged pleural drainage, protein losing enteropathy, pulmonary thromboembolism and death. We hypothesized that low pulmonary vascular compliance (PVC) is a risk factor for prolonged pleural effusion drainage after the Fontan operation. Material and Method: A retrospective review of 96 consecutive patients who underwent the Extracardiac Fontan procedures (median age: 3.9 years) was performed. Fontan risk score (FRS) was calculated from 12 categorized preoperative anatomic and physiologic variables. PVC $(mm^2/m^2{\cdot}mmHg)$ was defined as pulmonary artery index $(mm^2/m^2)$ divided by total pulmonary resistance $(W.U{\cdot}/m^2)$ and pulmonary blood flow $(L/min/m^2)$ based on the electrical circuit analogue of the pulmonary circulation. Chest tube indwelling time was log-transformed (log indwelling time, LIT) to fit normal distribution, and the relationship between preoperative predictors and LIT was analyzed by multiple linear regression. Result: Preoperative PVC, chest tube indwelling time and LIT ranged from 6 to 94.8 $mm^2/mmHg/m^2$ (median: 24.8), 3 to 268 days (median: 20 days), and 1.1 to 5.6 (mean: 2.9, standard deviation: 0.8), respectively. FRS, PVC, cardiopulmonary bypass time (CPB) and central venous pressure at postoperative 12 hours were correlated with LIT by univariable analyses. By multiple linear regression, PVC (p=0.0018) and CPB (p=0.0024) independently predicted LIT, explaining 21.7% of the variation. The regression equation was LIT=2.74-0.0158 PVC+0.00658 CPB. Conclusion: Low pulmonary vascular compliance is an important risk factor for prolonged pleural effusion drainage after the extracardiac Fontan procedure.

A Study of Mo Back Electrode for CIGSe2 Thin Film Solar Cell (CIGSe2 박막태양전지용 Mo 하부전극의 물리·전기적 특성 연구)

  • Choi, Seung-Hoon;Park, Joong-Jin;Yun, Jeong-Oh;Hong, Young-Ho;Kim, In-Soo
    • Journal of the Korean Vacuum Society
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    • v.21 no.3
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    • pp.142-150
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    • 2012
  • In this Study, Mo back electrode were deposited as the functions of various working pressure, deposition time and plasma per-treatment on sodalime glass (SLG) for application to CIGS thin film solar cell using by DC sputtering method, and were analyzed Mo change to $MoSe_2$ layer through selenization processes. And finally Mo back electrode characteristics were evaluated as application to CIGS device after Al/AZO/ZnO/CdS/CIGS/Mo/SLG fabrication. Mo films fabricated as a function of the working pressure from 1.3 to 4.9mTorr are that physical thickness changed to increase from 1.24 to 1.27 ${\mu}m$ and electrical characteristics of sheet resistance changed to increase from 0.195 to 0.242 ${\Omega}/sq$ as according to the higher working pressure. We could find out that Mo film have more dense in lower working pressure because positive Ar ions have higher energy in lower pressure when ions impact to Mo target, and have dominated (100) columnar structure without working pressure. Also Mo films fabricated as a function of the deposition time are that physical thickness changed to increase from 0.15 to 1.24 ${\mu}m$ and electrical characteristics of sheet resistance changed to decrease from 2.75 to 0.195 ${\Omega}/sq$ as according to the increasing of deposition time. This is reasonable because more thick metal film have better electrical characteristics. We investigated Mo change to $MoSe_2$ layer through selenization processes after Se/Mo/SLG fabrication as a function of the selenization time from 5 to 40 minutes. $MoSe_2$ thickness were changed to increase as according to the increasing of selenization time. We could find out that we have to control $MoSe_2$ thickness to get ohmic contact characteristics as controlling of proper selenization time. And we fabricated and evaluated CIGS thin film solar cell device as Al/AZO/ZnO/CdS/CIGS/Mo/SLG structures depend on Mo thickness 1.2 ${\mu}m$ and 0.6 ${\mu}m$. The efficiency of CIGS device with 0.6 ${\mu}m$ Mo thickness is batter as 9.46% because Na ion of SLG can move to CIGS layer more faster through thin Mo layer. The adhesion characteristics of Mo back electrode on SLG were improved better as plasma pre-treatment on SLG substrate before Mo deposition. And we could expect better efficiency of CIGS thin film solar cell as controlling of Mo thickness and $MoSe_2$ thickness depend on Na effect and selenization time.

Perspective of breaking stagnation of soybean yield under monsoon climate

  • Shiraiwa, Tatsuhiko
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2017.06a
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    • pp.8-9
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    • 2017
  • Soybean yield has been low and unstable in Japan and other areas in East Asia, despite long history of cultivation. This is contrasting with consistent increase of yield in North and South America. This presentation tries to describe perspective of breaking stagnation of soybean yield in East Asia, considering the factors of the different yields between regions. Large amount of rainfall with occasional dry-spell in the summer is a nature of monsoon climate and as frequently stated excess water is the factor of low and unstable soybean yield. For example, there exists a great deal of field-to-field variation in yield of 'Tanbaguro' soybean, which is reputed for high market value and thus cultivated intensively and this results in low average yield. According to our field survey, a major portion of yield variation occurs in early growth period. Soybean production on drained paddy fields is also vulnerable to drought stress after flowering. An analysis at the above study site demonstrated a substantial field-to-field variation of canopy transpiration activity in the mid-summer, but the variation of pod-set was not as large as that of early growth. As frequently mentioned by the contest winners of good practice farming, avoidance of excess water problem in the early growth period is of greatest importance. A series of technological development took place in Japan in crop management for stable crop establishment and growth, that includes seed-bed preparation with ridge and/or chisel ploughing, adjustment of seed moisture content, seed treatment with mancozeb+metalaxyl and the water table control system, FOEAS. A unique success is seen in the tidal swamp area in South Sumatra with the Saturated Soil Culture (SSC), which is for managing acidity problem of pyrite soils. In 2016, an average yield of $2.4tha^{-1}$ was recorded for a 450 ha area with SSC (Ghulamahdi 2017, personal communication). This is a sort of raised bed culture and thus the moisture condition is kept markedly stable during growth period. For genetic control, too, many attempts are on-going for better emergence and plant growth after emergence under excess water. There seems to exist two aspects of excess water resistance, one related to phytophthora resistance and the other with better growth under excess water. The improvement for the latter is particularly challenging and genomic approach is expected to be effectively utilized. The crop model simulation would estimate/evaluate the impact of environmental and genetic factors. But comprehensive crop models for soybean are mainly for cultivations on upland fields and crop response to excess water is not fully accounted for. A soybean model for production on drained paddy fields under monsoon climate is demanded to coordinate technological development under changing climate. We recently recognized that the yield potential of recent US cultivars is greater than that of Japanese cultivars and this also may be responsible for different yield trends. Cultivar comparisons proved that higher yields are associated with greater biomass production specifically during early seed filling, in which high and well sustained activity of leaf gas exchange is related. In fact, the leaf stomatal conductance is considered to have been improved during last a couple of decades in the USA through selections for high yield in several crop species. It is suspected that priority to product quality of soybean as food crop, especially large seed size in Japan, did not allow efficient improvement of productivity. We also recently found a substantial variation of yielding performance under an environment of Indonesia among divergent cultivars from tropical and temperate regions through in a part biomass productivity. Gas exchange activity again seems to be involved. Unlike in North America where transpiration adjustment is considered necessary to avoid terminal drought, under the monsoon climate with wet summer plants with higher activity of gas exchange than current level might be advantageous. In order to explore higher or better-adjusted canopy function, the methodological development is demanded for canopy-level evaluation of transpiration activity. The stagnation of soybean yield would be broken through controlling variable water environment and breeding efforts to improve the quality-oriented cultivars for stable and high yield.

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