• Korean Journal of Environmental Agriculture
• /
• v.38 no.3
• /
• pp.133-138
• /
• 2019

BACKGROUND: Production function gives the equation that shows the relationship between the quantities of productive factors used and the amount of product obtained, and can answer a variety of questions. This study was carried out to evaluate the relationship between irrigation water used for rice production and rice productivity by the production function which shows the mathematical relation between input and output. METHODS AND RESULTS: The statistical data on rice production and on the amount of irrigation water were used for the production function analysis. The analysis period was separated for 1966-1981 and 1982-2011, based on goal's change on agriculture from 'increasing food' to 'complex farming'. The relation between irrigation and yield considering production function is a short-term production function both before and after 1982. These results can be expressed by the sigmoid relation. When comparing the graphs of the two analyzed periods, there are differences in quantity between the maximum point and the minimum point during the same analysis period, which can be called an 'Irrigation Effect' by the difference of irrigation, and 'Technical Effect' by the difference by inputs like as fertilizers etc. CONCLUSION: The results could be useful as information for assessing the relationship between agricultural water and the productivity of rice and predicting rice productivity by irrigation water in Korea.

• Journal of Plant Biology
• /
• v.36 no.3
• /
• pp.203-210
• /
• 1993

In order to investigate the effects of plant hormones on the quantitative changes in mRNA of maize (Zea mays L.) rbcL, we used GA3, IAA, ABA and BAP. GA3 at the concentration of 10-4M resulted in decrease in rbcL gene transcript to 62%. IAA decreased the amount of rbcL transcript to about 70% at all the hormone concentrations tested. ABA did not cause a noticeable change in the amount of rbcL transcript, but BAP increased the amount of rbcL transcript to 153% at 10-8M and 123% at 10-5M, respectively. Thus, it appears that BAP is related to the increase in the amount of rbcL transcript by light.

• Restorative Dentistry and Endodontics
• /
• v.43 no.1
• /
• pp.3.1-3.10
• /
• 2018

Objectives: The aim of this study was to compare root canal volume change and canal transportation by Vortex Blue (VB; Dentsply Tulsa Dental Specialties), ProTaper Next (PTN; Dentsply Maillefer), and ProTaper Universal (PTU; Dentsply Maillefer) nickel-titanium rotary files in curved root canals. Materials and Methods: Thirty canals with $20^{\circ}-45^{\circ}$ of curvature from extracted human molars were used. Root canal instrumentation was performed with VB, PTN, and PTU files up to #30.06, X3, and F3, respectively. Changes in root canal volume before and after the instrumentation, and the amount and direction of canal transportation at 1, 3, and 5 mm from the root apex were measured by using micro-computed tomography. Data of canal volume change were statistically analyzed using one-way analysis of variance and Tukey test, while data of amount and direction of transportation were analyzed using Kruskal-Wallis and Mann-Whitney U test. Results: There were no significant differences among 3 groups in terms of canal volume change (p > 0.05). For the amount of transportation, PTN showed significantly less transportation than PTU at 3 mm level (p = 0.005). VB files showed no significant difference in canal transportation at all 3 levels with either PTN or PTU files. Also, VB files showed unique inward transportation tendency in the apical area. Conclusions: Other than PTN produced less amount of transportation than PTU at 3 mm level, all 3 file systems showed similar level of canal volume change and transportation, and VB file system could prepare the curved canals without significant shaping errors.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2008.11a
• /
• pp.89-92
• /
• 2008

This research analyzed the basic characteristics of unhardened concrete and the compression strength characteristics of hardened concrete according to liquidity retention agent mix rate change to improve the liquidity fluidity retention performance of high performance concrete, and produced the following results. The moment fluidity retention agent is added according to fluidity retention agent mix rate change, which increased fluidity retention agent mix rate, slump flow decreased, and in the case of slump flow according to the progress time change by the fluidity retention agent mix rates, the more fluidity retention agent mix rate increased, the lower slump flow change rate became. The moment fluidity retention agent is added according to fluidity retention agent mix rate change, fluidity retention agent mix rate increased compared to non-mixture of fluidity retention agent, and the air amount by progress time change by the fluidity retention agent mix rates slightly increased, however target range is still met and unit volume mass is inversely proportional to air amount. Compression strength according to age progress by the fluidity retention agent mix rates was shown to increase slightly with increase in fluidity retention agent mix rate, and yet the difference was not significant.

• Journal of Korean Society for Atmospheric Environment
• /
• v.26 no.1
• /
• pp.34-47
• /
• 2010

Long-range transport of air pollutants was simulated using Comprehensive Acid Deposition Model (CADM) and Yonsei University-Sulfuric Acid Deposition Model (YU-SADM). For the simulation, weather patterns that represent the four seasons were derived through a clustering analysis with 5-years of meteorological data. The simulation result showed that in spring, influenced by strong low pressure from China, air pollutants of moved to the Korean Peninsula. In summer, humid air moved into the Korean Peninsula across the Yellow Sea while the north pacific high pressure extended, making the concentration of air pollutants lower than that in the other seasons. In autumn, air pollutants were transported by the northwest wind caused by the movement of high pressure over the Yellow Sea, while in winter air pollutants were influenced by northwest winds from continental highs. The amount of air pollutants in each season showed that high amount of pollutants were transported in winter due to the strong northwest wind. The in-flows were 3 to 8 times higher than those of the other seasons, and out-flows were about as twice as high. The amount of wet deposition in summer and autumn increased significantly compared to the amount in the other seasons due to the increase of rainfall. Source-receptor relationship analysis for sulfur showed that 70 to 91 precent of the total deposition came from the self-contribution by the Korean Peninsula. In winter, contribution from China was about 25 percent of the total deposition which was higher amount than any other season.

• Korean Journal of Agricultural Science
• /
• v.40 no.3
• /
• pp.203-208
• /
• 2013

Differences in the filling amount of substrates in container can influence severely on the soil physical properties and crop growth. This research was conducted to secure the fundamental informations related to the changes in soil physical properties as influenced by the filling amount of coir dust-based substrates in container. For the experiment, three substrates were formulated by blending coir dust (CD) with expanded rice hull (CD+ERH, 8:2, v/v), carbonized rice hull (CD+CRH, 6:4, v/v) or ground and aged pine bark (CD+GAPB, 8:2, v/v). Based on the optimum bulk density, the amount of substrates filled in 347.5mL aluminum cylinder were adjusted to 90, 100, 110, 120, and 130%. Then the changes in total porosity (TP), container capacity (CC), and air-filled porosity (AFP) by various filling amounts were measured. The TP decreased linearly in CD+ERH and CD+GAPB and quadratically in CD+CRH as the filling amounts of the media increased from 90% to 130%. The CC in CD+ERH and CD+GAPB media increased as the filling amount increased from 90% to 120%, then decreased in 130%, showing quadratic change. The CC in CD+CRH was the highest in 90% filling amount and decreased gradually as the filling amount of root medea increased. The AFPs in CD+ERH and CD+GAPB media were 38 and 37%, respectively in 90% filling amount and they decreased drastically until 110% filling, then gradually in 120 and 130% filling amount showing the quadratic changes. The AFP of CD+CRH at 90% filling amount was 22% and it decreased as the filling amount increased until 130%, showing linear change. These results indicate that the increase in filling amount of substrates influenced more severely the AFP than CC, and careful consideration on container filling is required to provide a better root condition thus maximize crop growth.

• Journal of Korean Biological Nursing Science
• /
• v.3 no.2
• /
• pp.91-103
• /
• 2001

The bone is composed of the bone matrix of collagen and hydroxyapatite, the mixture of calcium and phosphours. The bone tissue is considered to the special connective tissue that possesses extracellular matrix made by collagen fiber deposited with mineral complex. In order to maintain bone mass measured by the sum of bone matrix and hydroxyapatite, bone resorption by osteoclast during lifetime and bone remodeling to form bone by osteoblast in its resorption region repeat continuously. The osteoblast has a mesodermic fetal origin like fibroblast for the formation of form tissues. Two cells express identical genes and synthesize the identical collagen type I as the major component of the formation of bone matrix and skin. Therefore, it is considered that the decrease of skinfold thickness and the decrease of bone mass related to the age, the change of two tissues composed of collagen type I is caused by the same genetic mechanism. The decrease of bone mass is caused by the change of the amount and structure of bone matrix by several factors and the amount of minerals deposited on bone matrix. Especially, in case of female, the deficiency of estrogen by menopause makes these changes rapidly increased. The decrease of bone mass and skinfold thickness is due to the decrease of the amount of collagen and its structural change the common component of bone tissue and skin tissue. Therefore, the relationship of the amount of cross-linked peptide N-telopeptide, collagen metabolite which excretes as urine. Based upon the proved results about the significant relationship of bone mass, the amount of bone collagen, the amount of skin collagen and skinfold thickness, the bone mass may be expected through a facile determination of skinfold thickness.

• Proceedings of the IEEK Conference
• /
• 2003.11a
• /
• pp.129-132
• /
• 2003

Fixed GOP allocation in MPEG-2 cannot cope with scene change and amount of motion, which results in degradation picture quality. By finding suitable N and M and allocating dynamic GOP, the improvement of picture quality can be achieved. In this paper, N and M are determined by scene change detection and estimation of amount of motion using color histogram per each macroblock. The simulation results show that the average PSNR is improved, especially around the shot boundaries.

• Proceedings of the KSME Conference
• /
• 2004.04a
• /
• pp.1114-1119
• /
• 2004

In a foaming process of microcellular plastics (MCPs) with a injection molding, research on the viscosity change that occurs when the gas is injected to the polymer has received little attention despite its importance. The purpose of this paper is to provide the basic data required to determine the processing condition by measuring viscosity changes against the gas injection rates of the blowing agent, and to verify the influence of the viscosity change on the flow condition of polymer inside the mold at the injection process.

• Archives of Plastic Surgery
• /
• v.32 no.5
• /
• pp.547-554
• /
• 2005

Orthognathic surgery for Class III malocclusion requires an elaborate preoperative planning using cephalometries or Mock surgery models which enable the surgeon to anticipate postoperative skeletal changes of maxilla and mandible as well as dentition. After surgery, patient's satisfaction is greatly influenced by appearance of soft tissue change. Therefore, it is imperative to predict a relatively accurate soft tissue change prior to surgery. A 5 year retrospective study was designed to evaluate the soft tissue change after sagittal split osteotomy of ramus(SSRO) for class III malocclusion. Analyses of preoperative and postoperative anthropometric measurements were performed. Patients who were treated only by SSRO for class III malocclusion and could follow up for 6 months were studied. Among them, the patients who had history of cleft palate and lip or hemifacial microsomia were excluded. Soft tissue changes were estimated by using the frontal and lateral photographs. Skeletal changes were observed by measuring amount of set back and angular changes of mandible to the reference line by using cephalometries. Relapses were also measured 6 months after the operation. We could observe skeletal changes were more profound than soft tissue changes concerning amount of set back, but soft tissue changes were also profound in angle. Relapse was more profound in skeleton than soft tissue but the amount was not significant. In spite of the variables which may affect proper assessment of the soft tissue change after skeletal relocation, this study can serve as a guide for exact prediction of the postoperative change of soft tissue and skeleton.