• Korean Journal of Plant Resources
• /
• v.19 no.2
• /
• pp.344-347
• /
• 2006

Watering methods for soybean sprouts could be mainly divided into two groups of overspraying and underwatering. The study was carried out to determine the effect of water supplying method on growth, morphological characteristics, colour and cutting resistance of soybean (cv. Junjery) sprouts and culture temperatures. The morphological characters, fresh and dry weights were measured on the 6th day after their culture, but daily mean temperatures inside the plastic culture boxes were measured by data-loggers. Lateral roots were more formed in the underwatering method (UM) than in the overspraying method (OM). Although their total lengths of both methods were nearly same, OM had longer hypocotyl but UM did longer root than the other. Middle and upper parts of hypocotyl were more thickened in UM than in OM. UM showed more hypocotyl fresh and dry weights than OM. There was, however, no significant difference between the two methods in cotyledon, root, total fresh and dry weights although the culture temperature was higher in OM than in UM.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2017.06a
• /
• pp.321-321
• /
• 2017

Water availability in rainfed lowlands (RFL) is strongly affected by climate change. In RFL, rice plants are exposed to soil moisture fluctuations (SMF) but rarely to simple progressive drought as widely believed. Typical RFL field is characterized by a about 5-cm thick high bulk density hardpan layer underneath the cultivated layer at about 20 cm depth that impedes deep root development. Root system has the ability to develop in response to changes in SMF, known as phenotypic plasticity. We hypothesized that genotypes that can adapt to RFL have root plasticity. The roots can sharply respond to re-wetting after drought period and thus penetrate the hardpan layer when the hardpan is wet and so becomes relatively soft, and thus access water under the hardpan. This study aimed to identify CSSLs derived from a cross between Sasanishiki and Habataki which adapted to such RFL conditions. We used 39 CSSLs together with the parent Sasanishiki, which were grown in hydroponics and pot under transient soil moisture stresses (drought and then rewatering), and compared with continuously well-watered (WW) (control) up to 14 days after sowing (DAS), and 20 DAS, respectively. Based on the results of hydroponics and pot experiments, we selected a few lines, which were grown in the soil-filled rootbox with artificial hardpan layer and without artificial hardpan. For the rootbox without artificial hardpan, plants were grown under WW and transient soil moisture stresses for 49 DAS. While the rootbox with artificial hardpan, the plants were grown under WW (control) and SMF (WW up to 21 DAS, 1st drought (22-36 DAS), rewatering (37-44 DAS), and followed by 2nd drought (45-58 DAS)). Among the 39 CSSLs, only CSSL439 (SL39) consistently showed significantly higher shoot dry weight (SDW) than Sasanishiki under transient soil moisture stress conditions as well as SMF conditions in all the experiments. Furthermore, under WW, SL39 consistently showed no significant differences from Sasanishiki in shoot and root growth in most of traits examined. SL39 showed significantly greater total root length (TRL) than Sasanishiki under transient soil moisture stress, which is considered as phenotypic plasticity in response to rewatering after drought period. Such plastic root development was the key trait that effectively contributed to root elongation and branching during the rewatering period and consequently enhanced the root to penetrate hardpan layer when the soil penetration resistance at hardpan layer reduced. In addition, using the rootbox with artificial hardpan layer ($1.7g\;cm^{-3}$, heavily compacted), SL39 showed greater root system development than Sasanishiki under SMF, which was expressed in its significantly higher TRL, total nodal RL, and total lateral RL at hardpan layer as well as at below the hardpan layer. These results prove that SL39 has plasticity that enables its root systems to penetrate hardpan layer in response to rewatering. Under SMF, such root plasticity contributed to its higher gs and Pn.

• Journal of Korean Society of Steel Construction
• /
• v.26 no.4
• /
• pp.299-309
• /
• 2014

HSA800 is a new high strength steel (HSS) plate for building structures developed by POSCO and RIST in 2011. It has upper and lower bounds for yield ($F_y$) and tensile ($F_u$) strength as of 650-770MPa and 800-950MPa, respectively, with yield ratio ($F_y/F_u$) limit as of 0.85 which make steel quality more reliable and enhance the seismic resistance of structures. As made by TMCP, it has a good weldability without increasing carbon percentage. The objective of this study is to provide alternative design of mega-structural members of the Lotte World Tower (555m, 123 story), a first super-tall building in Korea, using HSS considering structural safety, constructability, and cost-effectiveness. Steel outrigger trusses, belt-trusses and steel exterior columns were selected and analyzed to evaluate the structural performance between original and alternative designs using HSS. The results show that HSS can be applied to the members which do not affect lateral stiffness of a building and, in this study, approximately 1100tons of steel were saved. It implies that HSS can save overall construction costs - manufacturing, delivery, and erection costs - by reducing mega structural member size. HSA800 was very first applied to the Lotte World Tower based on the results of this study.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.22 no.1
• /
• pp.147-157
• /
• 2018

The basis of capacity design has been explicitly or implicitly regulated in most bridge design specifications. It is to guarantee ductile failure of entire bridge system by preventing brittle failure of pier members and any other structural members until the columns provides fully enough plastic rotation capacity. Brittle shear is regarded as a mode of failure that should be avoided in reinforced concrete bridge pier design. To provide ductility behavior of column, the one of important factors is that flexural hinge of column must be detailed to ensure adequate and dependable shear strength and deformation capacity. Eight small scale circular reinforced concrete columns were tested under cyclic lateral load with 4.5 aspect ratio. The test variables are longitudinal steel ratio, transverse steel ratio, and axial load ratio. Eight flexurally dominated columns were tested. In all specimens, initial flexural-shear cracks occurred at 1.5% drift ratio. The multiple flexural-shear crack width and length gradually increased until the final stage. The angles of the major inclined cracks measured from the vertical column axis ranged between 42 and 48 degrees. In particular, this study focused on assessing transverse reinforcement contribution to the column shear strength. Transverse reinforcement contribution measured during test. Each three components of transverse reinforcement contribution, axial force contribution and concrete contribution were investigated and compared. It was assessed that the concrete stresses of all specimen were larger than stress limit of Korea Bridge Design Specifications.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.53 no.1
• /
• pp.28-33
• /
• 2008

Traditionally mungbean (Vigna radiata L.) sprouts has been stored after dehydration to decrease their decay. The study was done to determine the effect of watering for final 12 hours of harvest day on morphological characters and color of mungbean sprouts. The seeds of cv. Zhong Lu 1 were soaked in 50 ppm BA solution immediately before 4 hour aeration and then cultured for 6 days, when water-supplied for final 12 hours or not. After packaged with PE envelops, the sprouts stored 5 days at $8^{\circ}C$, and their morphological characters, fresh and dry weights, and colors were measured everyday. Compared to non-water supplied, water supplied sprouts had thicker hypocotyl diameter in middle part, and higher total fresh weight due to increment of cotyledon and hypocotyl ones although the two sprouts did nearly same in other characters. Only nonwater supplied sprouts showed higher color b value in hypocotyl than water supplied ones although there were not significant differences between them in other color-related characters, meaning that the latter ones were more rapidly decayed during their storage. In non-water supplied sprouts, number of lateral roots, hypocotyl and root lengths, total fresh weight, brightness of hypocotyl and root was decreased since 3 days after storage but cutting resistance of hypocotyl was done since 5 days.

• Journal of Periodontal and Implant Science
• /
• v.37 no.2
• /
• pp.277-286
• /
• 2007

The edentulous posterior maxilla generally provides a limited amount of bone height because of atrophy of the ridge and pneumatization of the maxillary sinus, Maxillary sinus augmentation is one of the surgical techniques for reconstruction of the severely resorbed posterior maxilla. The purpose of this study was to evaluate the survival rate of implants and the long-term changes of graft height after maxillary sinus augmentation by lateral window approach. From September 1996 to July 2004, maxillary sinus augmentation with mixed grafts of autograft, allograft, xenograft and alloplast were performed on 45 patients and 100 implants were placed. We evaluated the survival rate of implants and the changes of BL(bone length)/IL(implant length) according to time using panoramic radiographs. The survival rate of implants was 91.0% for follow-up period. The mean reduction of graft heights was 0.34mm(3.0%) for 6 months and 1.22mm(1O.66%) for 3 years after augmentation. The total mean BL/IL was $1.34{\pm}0.21$ during 5 year observation period after augmentation and decreased slightly over time. The result means that graft materials were stable above the implant apex. BL/ILs of 1stage procedure were significantly decreased at 1-2 year, 3-4 year after augmentation and no statistically significant changes were observed in those of 2 stage procedure. The graft materials of both procedures were stable above the implant apex. No statistically significant changes of BL/IL were observed in the grafts combined with low amount of autogenous bone or without autogenous bone. The graft materials of both groups were stable above the implant apex. The results indicated that the placement of dental implants with maxillary sinus augmentation showed predictable clinical results and the grafts combined with low amount of autogenous bone or without autogenous bone had long-term resistance to resorption in maxillary sinus.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.46 no.1
• /
• pp.57-65
• /
• 2020

To prevent loss of hair protein during hair washing process by water through, a shield coating the pathway of water molecules was studied. Hydrophobic virgin hair, hydrophilic hair, which was damaged only methyleicosanoic acid (18-MEA) on the surface, and a repaired hair re-bound 18-MEA, were prepared and water mass changes by as heat were measured. Results showed that hydrophobic hairs followed bi-exponential function of 39 s and 151 s and other two hairs exhibited fast- and mono-exponential decay with 83 s, reflecting the extraction of water molecules without any resistance at the hydrophobic surface. On the assumption that hydrophobic surface resists an extraction of protein in water during the wash, the protein concentrations were compared from the hair of hydrophobic and hydrophilic surface. The extracted hair proteins were 179 and 148 ㎍/mL from the hair coated with hydrophilic polyethylene glycol (PEG) and hydrophobic polydimethylsiloxane (PDMS), respectively. This study suggested that hydrophobic coating on the hair surface could be used to prevent protein loss in wash, represented by LFM. In conclusion, this research provides some useful information to contribute to the development of hair washing products that can prevent protein loss in the cleaning process by granting hydrophobic coatings.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.32 no.3
• /
• pp.201-206
• /
• 2019

This report constitutes the first demonstration in Korea of single-crystal lateral gallium oxide ($Ga_2O_3$) as a metal-oxide-semiconductor field-effect-transistor (MOSFET), with a breakdown voltage in excess of 480 V. A Si-doped channel layer was grown on a Fe-doped semi-insulating ${\beta}-Ga_2O_3$ (010) substrate by molecular beam epitaxy. The single-crystal substrate was grown by the edge-defined film-fed growth method and wafered to a size of $10{\times}15mm^2$. Although we fabricated several types of power devices using the same process, we only report the characterization of a finger-type MOSFET with a gate length ($L_g$) of $2{\mu}m$ and a gate-drain spacing ($L_{gd}$) of $5{\mu}m$. The MOSFET showed a favorable drain current modulation according to the gate voltage swing. A complete drain current pinch-off feature was also obtained for $V_{gs}<-6V$, and the three-terminal off-state breakdown voltage was over 482 V in a $L_{gd}=5{\mu}m$ device measured in Fluorinert ambient at $V_{gs}=-10V$. A low drain leakage current of 4.7 nA at the off-state led to a high on/off drain current ratio of approximately $5.3{\times}10^5$. These device characteristics indicate the promising potential of $Ga_2O_3$-based electrical devices for next-generation high-power device applications, such as electrical autonomous vehicles, railroads, photovoltaics, renewable energy, and industry.

• Journal of the Korean Geosynthetics Society
• /
• v.21 no.4
• /
• pp.101-109
• /
• 2022

This study describes the results of model experiment to analyze the effect of backfill material types on the behavior of underground facility. In the model experiment, backfill materials around the existing underground facility were applied with soil (Jumunjin standard sand) and CLSM. The displacement of underground facility was analyzed for each excavation stage considering the separation distance between the excavation surface and the backfill area based on the experimental results. When soil was applied as a backfill material, the soil on the back of the excavation surface collapsed by excavation and formed an angle of repose, and the process of slope stability was repeated at each excavation stage. In addition, the displacement of underground facility began to occur in the excavation stage that the failure line of soil passes the installation location of the underground facility. When CLSM was applied as a backfill material, there was almost no horizontal and vertical displacement of the ground regardless of the separation distance from the excavation surface even when excavation proceeded to the backfill depth. Therefore, this result showed that it can have a resistance effect against the lateral earth pressure generated and the collapse of the original ground by adjacent excavation, if a backfill material with high stiffness such as CLSM is applied.

• Journal of Korea Entertainment Industry Association
• /
• v.15 no.8
• /
• pp.363-377
• /
• 2021

The present study investigated the effects of dynamic tubing gait training(I and II) on the postural alignment, gait, and quality of life in chronic patients with Parkinson's disease. This study is based on the case study that recruited a total of 3 patients with chronic Parkinson's disease (Hoehn and Yahr Stage of 1 to 3 each one person). Dynamic tubing gait training (I and II) applied to chronic patients with Parkinson's disease for 25 sessions, 30 minutes a day, 5 days a week, over 5 weeks period. To investigate the effects of this study, evaluating using the postural alignment test, muscle activity tests, gait analysis, and quality of life scale for patient with Parkinson's disease. After the intervention of Dynamic tubing gait training (I and II), Trunk flexion was decreased. Also, during walking from initial contact (IC) to mid stance (Mst), muscle activity of Quadriceps, Hamstring, and Tibialis Anterior (TA) was increased and muscle activity of Gastrocnemius was decreased. The muscle activation of Erector Spinae (ES T12, L3) was increased in the H&Y I and III stages and decreased in the H&Y II stage. Length of gait line, single support line, ant/post position and lateral symmetry of center of pressure (COP) parameters improved. The spatio-temporal gait parameters including of step length, stride length, and velocity was increased, and cadence decreased. Further the quality of life of patients with Parkinson's disease was improved. Based on these findings, Dynamic tubing gait training (I and II) could be applied as a new approach to improve posture, gait, quality of life in chronic patients with Parkinson's disease for more than 5 years, whose drug resistance is halved.