• Korean Journal of Materials Research
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• v.33 no.5
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• pp.175-188
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• 2023

Water electrolysis holds great potential as a method for producing renewable hydrogen fuel at large-scale, and to replace the fossil fuels responsible for greenhouse gases emissions and global climate change. To reduce the cost of hydrogen and make it competitive against fossil fuels, the efficiency of green hydrogen production should be maximized. This requires superior electrocatalysts to reduce the reaction energy barriers. The development of catalytic materials has mostly relied on empirical, trial-and-error methods because of the complicated, multidimensional, and dynamic nature of catalysis, requiring significant time and effort to find optimized multicomponent catalysts under a variety of reaction conditions. The ultimate goal for all researchers in the materials science and engineering field is the rational and efficient design of materials with desired performance. Discovering and understanding new catalysts with desired properties is at the heart of materials science research. This process can benefit from machine learning (ML), given the complex nature of catalytic reactions and vast range of candidate materials. This review summarizes recent achievements in catalysts discovery for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). The basic concepts of ML algorithms and practical guides for materials scientists are also demonstrated. The challenges and strategies of applying ML are discussed, which should be collaboratively addressed by materials scientists and ML communities. The ultimate integration of ML in catalyst development is expected to accelerate the design, discovery, optimization, and interpretation of superior electrocatalysts, to realize a carbon-free ecosystem based on green hydrogen.

• Journal of the Korean Society for Precision Engineering
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• v.12 no.11
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• pp.27-35
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• 1995

The fluid coupling combined with a pump and a turbine have many merits compared with other couplings, their uses are increesing rapidly in various industrial fields at home and abroad in pursuit of high-speed more efficiency durability of various mechanic devices. The authorities concerned have recognized the improtance of the fluid coupling and supported its developement and now some trial products began to show up. As the structrue and characteristics of the fluid coupling have little similarity to other kinds of couplings and its fluid behavior is unique, so its characteristic analysis is expected to be difficult. Until now no satisfactory study on the characteristics of the fluid coupling seems to have been conducted at home, so a study on this field needs to be done urgently. The purpose of this research is to construct the experimental test set-ups and establish a series of performance test program for the domestically developed fluid couplings and to provide a software to store and utilize these experimental data which can be used to improve the performance of the fluid coupling and solve on the job problems confronted in operation. The performance test consists of taking measurment of torque, rpm and efficiency of the fluid coupling for three different amount of working fluid inside with various loads to the output shaft and finally infestigating the torque, rpm and efficiency characteristics of the fluid coupling with respect to these parameters. The results of this study can contribute valuable references to the development of variable speed fluid coupling and torque converter currently pursued by the domestic industry.

• IMMUNE NETWORK
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• v.24 no.1
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• pp.9.1-9.21
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• 2024

The cytokine IL-7 plays critical and nonredundant roles in T cell immunity so that the abundance and availability of IL-7 act as key regulatory mechanisms in T cell immunity. Importantly, IL-7 is not produced by T cells themselves but primarily by non-lymphoid lineage stromal cells and epithelial cells that are limited in their numbers. Thus, T cells depend on cell extrinsic IL-7, and the amount of in vivo IL-7 is considered a major factor in maximizing and maintaining the number of T cells in peripheral tissues. Moreover, IL-7 provides metabolic cues and promotes the survival of both naïve and memory T cells. Thus, IL-7 is also essential for the functional fitness of T cells. In this regard, there has been an extensive effort trying to increase the protein abundance of IL-7 in vivo, with the aim to augment T cell immunity and harness T cell functions in anti-tumor responses. Such approaches started under experimental animal models, but they recently culminated into clinical studies, with striking effects in re-establishing T cell immunity in immunocompromised patients, as well as boosting anti-tumor effects. Depending on the design, glycosylation, and the structure of recombinantly engineered IL-7 proteins and their mimetics, recombinant IL-7 molecules have shown dramatic differences in their stability, efficacy, cellular effects, and overall immune functions. The current review is aimed to summarize the past and present efforts in the field that led to clinical trials, and to highlight the therapeutical significance of IL-7 biology as a master regulator of T cell immunity.

• Health Policy and Management
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• v.8 no.2
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• pp.125-148
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• 1998

Accurate vital statistics are essential for a national health planning and evaluation. Among various vital statistics, birth and death rates, and infant and matemal mortality rates together with the causes of death are the very basic ones for above purposes as well as for the maternal and child health management. These statistics are based on the birth and death reports. It is required by law to report every birth and death within one month after its occurrence. However, in case of a neonatal death occurring prior to the birth report, most of the birth and death are not reported. Thus accurate infant and maternal mortality rates are not available yet in Korea. The main objective of this study is to develop a birth and infant death reporting system via computer network. We designed a new birth report form based on the current form and data from the analysis of medical record forms of 14 hospitals. A new form is basically addition of essential medical information to the current birth report form. Since a revision of the rules and regulations related wtih the birth report is necessary to use a new form, we kept the current from intact to make it acceptable to the government office for a field trial. We also developed computer programs for data input for birth and death reports at a medical faciltiy, data processing for production of maternal and child health indices at a health center, and management of maternal and child health services including immunization and postantal care at health center. The birth certificate and birth report can be printed out at a medical facility. The computer packages were programmed by Borland Delphi 3.0 and can be run under Windows 95 system. We proposed a new birth and death reporting system via computer network after a field trial for data input, transmission, and processing. The medical and demographic data o birth and death at medical facilities will be sent to health centers directly via computer network. The health center will retain the medical data for analysis and forward only the data for birth and death reports required by current regulations to the Dong, Up, or Myun Office. Once the birth or death is reported via computer network to the Dong Office, then the Dong Office will notify the baby's mother of the birth report and request to submit the baby's name by mail. When the baby's name its submitted. the Dong Office will forward the birth reports to the Common Court and Statistics Agency in the same way as the current system, Upon the completion of birth registration of the Common Court, the court will issue the birth certificate to mother which will be used in lieu of the family record. The advantages of proposed birth and death reporting system via computer network ar as follows ; I) The accuracy, timing, and completeness of reporting will be improved and more accurate maternal and child health indices can be obtained, ii) The maternal and child health services of health center will be obtained, iii) Epidemiologic data for pregnancy and birth can be obtained, iv) Manpower for birth and death reporting will be saved.

• Korean Journal of Breeding Science
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• v.41 no.4
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• pp.630-634
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• 2009

"Hyedang", a new covered cultivar derived from the crosses between "Suwon300" and "Haganemugi//CI08397/Haganemugi" developed at the Honam Agricultural Research Institute (HARI), NICS, RDA in 2007. The origin of "Hyedang" is "Iksan 407" (SB951033-B-B-B-72). The initial cross was made in 1995 and the selected line showed a high yield and good quality characteristics under yield trial test in 2004. "Iksan407" consistently performed well for three years (2005-2007) from the four locations of regional yield trial (RYT) in Korea and released as "Hyedang". The characteristics of "Hyedang" were the following: rate III growth habit, green leaf and stem, compact spike and with long rough awns. The heading date was April 25 in upland and April 17 in paddy field, which was 2 and 3 days earlier than that of check cultivar, "Olbori". The culm length was 80 cm which was 8 cm shorter than those of check cultivar. It showed spike length of 4.3 cm and 696 spikes per $m^2$, 51 grains per spike, 35.0 g of 1,000 grain weight and 704 g of test weight. It showed stronger winter hardiness and higher resistance to barley yellow mosaic virus (BaYMV) than those with check cultivar. It showed similar protein content and higher whiteness than those of the check cultivar and diastatic power was higher than that of Olbori. The average yield of the pearled grain in the RYT was $4.17ton\;ha^{-1}$ in upland and $4.27ton\;ha^{-1}$ in paddy field, which was 23% and 9% higher than that of the check cultivar, respectively. This cultivar would be suitable for the area above the daily minimum mean temperature of $-8^{\circ}C$ in January in Korean peninsula.

• Korean Journal of School Psychology
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• v.9 no.3
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• pp.485-503
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• 2012

Academic engagement has been known as a strong predictor of students' cognitive and affective outcomes in an educational context. Despite increasing interest and theoretical usefulness of this construct, a few researchers seem to be interested in the validation of instruments to measure academic engagement for Korean students. Thus, this study would like to introduce one of academic scales widely used, UWES-S(Utrecht Work Engagement Scale-Student) (Schaufeli et al., 2002a: 2002b) and to validate the UWES-S for Korean college students. To validate the Korean version of the UWES-S, 651 college students (285 for Field Trial, 366 for Main Study) were used. The procedure is as follows. First, we used an integrated adaptation procedure to produce a Korean version of the UWES-S. Second, EFA(exploratory factor analyses) was applied to explore the factor structure of the UWES-S on the field trial data. Third, the psychometric properties of the UWES-S items were examined by graded response model(GRM). Also CFA(confirmatory factor analysis) was used to examine its internal construct validity for the data from the main study. Finally, the external validity of the UWES-S was scrutinized with the related variables such as academic motivation and satisfaction. As a result, the Korean version of the UWES-S with 13 items was accepted that the four items were excluded from its original version. Second, the internal validity was supported that the 3 factor CFA model(vigor, dedication, absorption) fit the data well. Third, we supported the partial mediation model that academic engagement played as a mediating variable between academic motivation(internal/external) and academic satisfaction. Finally, the differences between a validation of UWES-S for Korean college and high school students, the necessity of construct equivalence testing, and direction for future research of scale validating were discussed.

• Korean Journal of Soil Science and Fertilizer
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• v.17 no.3
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• pp.258-264
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• 1984

Pot and field experiments were conducted to find out the effects of lime application on growth and Cd uptake of paddy rice in Cd added and contaminated soils. Lime application to soil-applied Cd could reduce Cd content in brown rice as well as increasing rice yields compared to that of no lime. The optimum requirement of lime to maintain Cd content in brown rice below 0.4 ppm (precaution concentration) were 56,381 and 512kg/10a at 3, 6 and 12 ppm of Cd in soil by pot experiment and 142.7 and 623.9kg/10a at 1.5 and 5.4 ppm of Cd in soil by field trial, respectively. The recommendable soil pH before transplanting to keep the Cd content in brown rice below 0.4 ppm were 5.2, 7.2 and 7.5 at 3, 6 and 12 ppm of Cd in soil, respectively.

• Journal of Plant Biotechnology
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• v.32 no.4
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• pp.243-250
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• 2005

The coat protein gene (AF296280) of the Korean isolate Potato leafroll virus (PLRV) was cloned and the open reading frame (627 bp) was transformed into potato (Solanum tuberosum cv. Superior). Out of seventeen individual transgenic lines, five lines were identified to confer resistance to PLRV through the five generation's selection program in the greenhouse as well as isolated trial field. Successful introduction and genetic stability of coat protein gene in the genome of potato were confirmed by polymerase chain reaction (PCR), Southern blot hybridization and northern blot hybridization. Some of the transgenic lines were highly resistant to PLRV but did not show any resistance to less homologous Potato virus Y (PVY). Our results suggest that the resistance to PLRV is due to homology dependent gene silencing by sense strand coat protein gene. In addition, the results of field test through five generations showed that there were no significant differences comparing to nontransgenic potatoes in the morphological aspect of shoot as well as tuber, Ho remarkable differences were also observed in the major agronomic characters and yields except for the resistance to PLRV.

• Korean Journal of Soil Science and Fertilizer
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• v.22 no.3
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• pp.228-233
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• 1989

Successive changes of transpiration by the tobacco plant during the growing season with pot trial treated with 30cm and 100cm ground water tables were compared with change of soil moisture content in rhizospere of field under natural rainfall conditions. Transpiration from the 41st to the 60th day after transplanting was the highest showing about 50% of total transpiration of whole cultivation period. As the result, soil moisture condition in rhizospere of field was kept insufficiently during the above period. Transpiration by the plant was so remarkably affected by the meteorological environment that the transpiration on rain-cloudy day was one third of that on clear day at middle stage of the growth. Maximum transpiration in a clear day was obtained from 14:00 to 16:00 at the 58th day after transplanting.

• Economic and Environmental Geology
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• v.47 no.3
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• pp.275-289
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• 2014

Recent scaled-up onshore and offshore field production tests revealed that the expectancy to produce gas from the gas hydrate deposits is gradually increasing, recognizing its potentials as one of the future energy resources. The total produced gas was approximately $480m^3$ by the hot water circulation method for 6 days' operation in Mallik 2002 project in Canada. In Mallik 2006-2008 project, the gas was successfully produced stably by the depressurization method for 6 days, up to $13,000m^3$ cumulatively. The depressurization method applied in the Mallik test was revealed as an effective way to produce gas from gas hydrates. The Alaska North Slope field trial in 2012 to inject mixed gas of $CO_2$ and $N_2$ to exchange $CH_4$ was successfully completed for the first time to produce maximum $1,270m^3$ per day. The remarkable achievement is that Japan has completed first offshore production test in the Eastern Nankai Trough, and produced approximately $120,000m^3$ of methane by the depressurization method for 6 days in March 2013. The technical challenges and uncertainties obtained from Nankai Trough production test give Korea more considerations in the aspects of well completion, reservoir formation and seafloor stability, sand control, flow assurance, and etc., due to the different geological environments and geomechnical properties in Ulleung Basin in Korea.