• Journal of Veterinary Clinics
• /
• v.37 no.2
• /
• pp.61-66
• /
• 2020

Nickel is a nutritionally essential trace element that plays an important role in the immune system of several animal species. The aim of this study was to examine the effect of nickel chloride on chemotactic activity of peripheral blood polymorphonuclear cells (PMNs) and whether this effect is associated with interleukin (IL)-8 and a nuclear factor-kappa B (NF-κB)-dependent pathway. Peripheral blood mononuclear cells (PBMCs) and PMNs were isolated by Percoll solution (Specific gravity; 1.080) and 1.5% dextran treatment, respectively. A modified Boyden chamber assay was used to measure the chemotactic activity of PMNs. The level of IL-8 in culture supernatant from PBMCs was measured by enzyme-linked immunosorbent assay (ELISA). Both of PBMCs and PMNs exhibited a low viability when cultured with concentration of greater than 1,000 μM of nickel chloride for 24 h. Thus, nickel chloride was used at concentration of 500 μM, which preserved cell viability. Treatment with nickel did not directly affect the chemotactic activity of PMNs. However, the chemotactic activity of PMNs was remarkably increased by culture supernatant from PBMCs treated with nickel chloride (500 μM) for 24 h. Recombinant porcine IL-8 polyclonal antibody (pAb) neutralized the enhancing effect on the chemotactic activity of PMNs by culture supernatant from PBMCs treated with nickel and this culture supernatant had higher IL-8 levels than the culture supernatant from untreated PBMCs. In addition, n-tosyll-phenylalanine chloromethyl ketone (TPCK), a NF-κB inhibitor, antagonized the enhancing effect on the chemotactic activity of PMNs by the culture supernatant from PBMCs treated with nickel. These results suggested that nickel stimulates porcine PBMCs to produce IL-8, which increases the chemotaxis of PMNs via NF-κB-dependent pathway.

• Korean Journal of Optics and Photonics
• /
• v.24 no.3
• /
• pp.111-119
• /
• 2013

A large aspheric mirror is a key component for large astronomical telescopes and high resolution satellite cameras. Since it is large and has an aspheric form, it is much more difficult to fabricate it compared to the similar size of spherical mirror. Especially, the opto-mechanical design and analysis is critical to reduce the deformation of mirror surface due to the external forces such as gravity or temperature change, as the mirror size is larger and lightweighting ratio is increased. The design requirements for the mirror are different depending on the particular ground and space applications because the environmental conditions are changed. In this paper, we explain the opto-mechanical design and analysis for ground and space applications that are among the most difficult to achieve among several technologies related to development of the large aspheric mirror.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.37 no.5
• /
• pp.379-388
• /
• 2019

Recently, a technique for acquiring spatial information data using UAV (Unmanned Aerial Vehicle) has been greatly developed. It is a very crucial issue of the GIS (Geographic Information System) mapping system that passes way point in the unmanned airframe and finally measures the accurate image and stable localization to the desired destination. Though positioning using DGPS (Differential Global Navigation System) or RTK-GPS (Real Time Kinematic-GPS) guarantee highly accurate, they are more expensive than the construction of a single positioning system using a single GPS. In the case of a low-priced single GPS system, the stability of the positioning data deteriorates. Therefore, it is necessary to supplement the uncertainty of the absolute position data of the UAV and to improve the accuracy of the current position data economically in the operating state of the UAV. The aim of this study was to present an algorithm enhancing the stability of position data in a single GPS mode of UAV with multiple GPS. First, the arrangement of multiple GPS receivers through the center of gravity of the UAV were examined. Next, MD (Mahalanobis Distance) is applied to detect instantaneous errors of GPS data in advance and eliminate outliers to increase the accuracy of previously collected multiple GPS data. Processing procedure for multiple GPS reception data by applying the center of the triangular method were presented to improve the position accuracy. Second, UAV navigation systems integrated multiple GPS through configuration of the UAV specifications were implemented. Using the unmanned airframe equipped with multiple GPS receivers, GPS data is measured with the TCM (Triangular Center Method). In addition, UAV equipped with multiple GPS were operated in study area and locational accuracy of multiple GPS of UAV with VRS (Virtual Reference Station) GNSS surveying were compared. The result showed that the error factors are compensated, and the error range are reduced, resulting in the reliability of the corrected value. In conclusion, the result in this paper is expected to realize high-precision position estimation at low cost in UAV using multiple low-cost GPS receivers.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
• /
• v.18 no.4
• /
• pp.12-21
• /
• 2022

Steam assisted gravity drainage(SAGD) is a process that drills well in the underground oil sands layer, injects hightemperature steam, lowers the viscosity of buried bitumen, and recovers it to the ground. Recently, direct contact steam generator(DCSG) is being developed to maximize steam efficiency for SAGD process. The DCSG requires high technology to achieve pressurized combustion and steam generation in accordance with underground pressurized conditions. Therefore, it is necessary to develop a combustion technology that can control the heat load and exhaust gas composition. In this study, process analysis of high-pressurized DCSG was conducted to apply oxygen enrichment technology in which nitrogen of the air was partially removed for increasing steam production and reducing fuel consumption. As the process analysis conditions, methane as the fuel and normal air or oxygen enriched air as the oxidizing agent were applied to high-pressurized DCSG process model. A simple combustion reaction program was used to calculate the property variations for combustion temperature, steam ratio and residual heat in exhaust gas. As a major results, the steam production efficiency of DCSG using the pure oxygen was about 6% higher than that of the normal air due to the reducing nitrogen in the air. The results of this study will be used as operating data to test the demonstration device.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.30 no.2
• /
• pp.211-219
• /
• 2004

Yew (Taxus cuspidata Sieb.) chose that grow as medicine, food, decorative plant in Korea's Kyong-Gi province surroundings. Extracts of yew extracted leaf of 250g and stems of 300g with 1,3-butylene glycol (l,3-BG), propylene glycol (PG) and water. As results, external appearance of leaf extract of yew was slightly brown clear extract. The pH was 5.3${\pm}$0.5, and specific gravity was 1.012${\pm}$0.05, and refractive index was l.375${\pm}$0.05. Also, appearance of stem's extract was slightly brown clear extract, and the pH was 5.4${\pm}$0.5, and specific gravity was 1.016${\pm}$0.05, and refractive index was 1.358${\pm}$0.05. Oil of yew separated from seeds, and extracted polysaccharide high purity from fruits. As a result, specific gravity of oil was 0.987, and obtained 40.0% of yield. Total polyphenols amount of yew extract is detected 0.563% in leaves, 0.325% in stems, whereas total tannins amount contained 0.054% and 0.037% each in leaves and stems. As effect in cosmetics, the anti-oxidative effect by DPPH method is 75.0% in leaves, and stems was 64.0%. Collagen synthesis rate was shown high activity by 54.16% in stem's extract, 33.18% in leaves' extract. Also, PPE-inhibitory activities were 13.7% and 23.5% each in leaves and stems. Anti-inflammatory effect of yew seed oil displayed superior effect of 41% than control. Polysaccharide's molecular weight that is gotten from fruits was 5${\times}$10$^4$-3${\times}$10$\^$5/ dalton, and got 20.0${\pm}$5% of yield.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.31 no.4D
• /
• pp.539-546
• /
• 2011

Traffic accident collision interpretation is composed of various shapes, and speed variations working to the vehicle during collision are utilized as a very important factor in evaluating collision degrees between vehicles and safety of passengers who got in the vehicle. So, methods of interpreting results on speed variations utilizing simulation programs on the collision interpretation become necessary. By the way, reliability evaluation on each program is being required because various collision interpretations simulations are spread widely. This study utilized collision interpretation programs such as EDSMAC and PC-CRASH adopting completely different physical approaches, and then carried out collision experiments of one-dimensional front and two-dimensional right angle while changing values of a lot of collision factors such as vehicle's weight, center of gravity, rolling resistance, stiffness coefficient, and braking forces among early input conditions. Also, the study recognized effects of collision factors to speed variations as output results during crashing. As a result of this research, two simulation programs showed same speed variations together on the vehicle's weight, center of gravity, and braking forces. Stiffness coefficient of the vehicle reacted to EDSMAC only, and rolling resistance coefficient did not affect any particular influences on speed variations. However, there appeared a bit comparative differences from the speed variation's values, and this is interpreted as responding outcomes by applying fixed properties values to each simulation program plainly. Therefore, reliability on analysis of traffic accident collisions shall be improved by doing speed analysis after taking the fixed value of simulation programs into consideration.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.37 no.3
• /
• pp.1-10
• /
• 2009

Wooded areas that are a part of school campuses are one type of urban forest. Most schools located in an urban environment make an excellent setting for a forest in terms of location and area. These kinds of wooded spaces also make the city greener and healthier. As a place where students spend a great deal of time, schools can also be a venue for environmental education. The creation of wooded areas in schools currently has focused on the end result only; by ignoring student needs and participation, these areas have not had a significant influence on student environmental education. Previous studies based on questionnaire survey are significant in that they have quantified subjective qualitative data via Likert Scale. There has been, however, a problem in quantifying the more ambiguous subjective data. Therefore, this paper has attempted to investigate those factors that have an influence on student satisfaction with the wooded areas of their school campus using Fuzzy Theory with elementary school students in Gyeongsangbuk-do. A change was observed in terms of the ranking of arithmetic mean values of 'school peculiarity' and 'emotion evolution' and center of gravity, which has adopted Fuzzy Theory, proving that Fuzzy Theory could rationally objectify qualitative data such as human thoughts. In terms of the influential factors on the satisfaction with school forests(regression coefficient), 'school uniqueness(0.159)' was the highest, followed by 'many trees(0.142),' 'importance of nature(0.136)' and 'emotion evolution(0.130).' This paper may therefore be useful as basic data for objective questionnaire surveys and the development of school forests.

• Korean Journal of Applied Biomechanics
• /
• v.17 no.4
• /
• pp.17-25
• /
• 2007

The purpose of the study is to give basic data for the improvement of the skill and to show an exemplary position for squash club members or trainers thru a comparative analysis on the kinematics and kinetics variables on the forehand drive motion in playing squash. The objects of the research are divided into two sections, skilled group(n=8) and unskilled group(n=8). The skilled group is composed of professional players currently working and unskilled group is career of six month, both of lives in B city. In this research, to gather the data 3D motion analysis and test result analysis using force platform was used. The variables are duration, position, segment velocity, segment acceleration and etc. in using force platform. The results are as follows: 1. The duration per phase of the skilled is 0.18sec P1(DS) while that of unskilled is 0.32sec. in P2(FT), the duration of the skilled is 0.29sec, that of unskilled is 0.34sec. Average of the duration of the skilled is 0.48sec, while the unskilled, 0.66sec. 2. Regarding positional movements per event, the unskilled has a relatively higher position in center of gravity, shoulder joint, elbow joint compared with that of the skilled. Generally speaking, positions of the unskilled is higher than the skilled. 3. In segment velocity per event, R-shank, R-upper arm, R-forearm and racket. The skilled is faster than the unskilled. we found a big dig difference in shank. 4. In acceleration per event, there was a big difference in upper-arm and fore-arm of the impact. 5. The skilled group on the force platform shows relatively stable and regular changes while the unskilled shows unstable from the touch down to initial 20% the force value of central support period after the impact moment decreases rapidly and the center of gravity is not moved well. 6. The maximum force value of the skilled is 1019.7N. it is found 19.86% of the total duration. That of the unskilled is 639.2N, it is found 20.67% of total duration.

• Journal of The Korean Society of Integrative Medicine
• /
• v.8 no.3
• /
• pp.33-41
• /
• 2020

Purpose : Conventional Balance Measurement can only measure the center of gravity and the shaking movement of the body. As a result, it has the disadvantages of not responding to visual changes and blocking functions of variables. This study was carried out to evaluate the performance of new equipment that measures the balance of the body using changes in body segment and pressure using the acceleration sensor to compensate for the disadvantages of the existing equipment. Methods : To this end, balance ability was measured in 43 healthy male/female adults without orthopedic injuries and nervous system damage in the last 6 months. in a situation where the visual information was restricted by Virtual Reality (VR) gear, all subjects measured and evaluated the balance ability utilizing the new equipment. Balance measurement (Prime Medilab, Korea) and Wii fit (Nintendo, Japan) were used to measure the balance ability of the subjects, and the balance ability test was performed in 4 postures using each device for data acquisition. The test duration for each posture was 30 seconds. For data acquisition, the average value of three experiments measured using each equipment was analyzed, and the statistical test was performed using the independent sample and the corresponding sample t-test, and the significance level was set to α=.05. Results : As a result of measuring the balance ability using individual equipment, blocking visual information using VR gear, the average speed, maximum speed, and moving area of the COP increased equally. It was found that the obtained absolute size of the result in Wii was somewhat larger than that of BM. Conclusion : It is considered that in the future research, it is necessary to measure changes in the body's center of gravity through image analysis, etc., to make clear comparison and evaluation of the usability.

• Korean Journal of Applied Biomechanics
• /
• v.16 no.2
• /
• pp.97-108
• /
• 2006

C. H. OH, S. N. CHOI, T. G. NAM, The Kinematic Analysis of the Tennis Flat Serve Motion, Korean Jiurnal of Sports Biomechanics, Vol. 16, No. 2, pp. 97-108, 2006. By the comparison and the analysis of the different factors during the tennis flat serve motion such as the required time per section, the movement displacement of the racket, the velocity of the upper limbs joints, the physical center of gravity, and the angle and the angular velocity of the upper limbs joints between an ace player and a mediocre player, these following results were drawn. First, the experiment result of the total time required per section in a tennis flat serve motion showed that an ace player was faster than a mediocre player by 0.4 seconds. This result suggested that it was required to increase the speed of the racket head by a swift swing to perform an effective flat serve motion. Second, the experiment result of the movement displacement of the racket in the tennis flat serve motion showed that an ace player greatly moved toward the left side on an x-axis. But both an ace and a mediocre player were shown to be at the similar points on a y-axis at the moment of the impact of the racket. An ace player was also shown to be located at a higher position on a z-axis by 0.23m. Third, the velocity of the center of gravity of an ace player was faster in every phase than that of a mediocre player in a tennis flat serve motion. Fourth, the velocity of the upper limb joints of an ace player was faster in every phase than that of a mediocre player in a tennis flat serve motion. Fifth, the experiment result of the speed of the racket head in tennis flat serve motion showed that a mediocre player was faster than an ace player in the first phase, but the latter was faster than the former in the second, third, and the fourth phases. Sixth, at the moment of impact of a tennis flat serve, an ace player had greater flexion of the angle of the wrist joints by an 11.8 degree than a mediocre player. An ace player also had greater extension of the angle of the elbow joint and the shoulder joint respectively by a 5.2 degree and a 1.4 degree with a mediocre player. Seventh, an ace player had greater angular velocity of the upper limb joints and the hip joints than a mediocre player at the moment of the impact of tennis flat serve. Eighth, an ace player was shown to have a greater change of the forward and the backward inclination (or the anterior and posterior inclination) of the upper body