• Journal of Energy Engineering
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• v.19 no.2
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• pp.128-135
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• 2010

This paper introduces step by step procedures for the fabrication and operation of an embedded solar tracker. The system presented consists of application software, compactRIO, C-series interface module, analogue input module, step drive, step motor, feedback devices and other accessories to support its functional stability. CompactRIO that has a real-tim processor allows the solar tracker to be a stand-alone real time system which operates automatically without any external control. An astronomical method and an optical method were used for a high-precision solar tracker. CdS sensors are used to constantly generate feedback signals to the controller, which allow a solar tracker to track the sun even under adverse conditions. The database of solar position and sunrise and sunset time was compared with those of those of the Astronomical Applications Department of the U.S. Naval Observatory. The results presented here clearly demonstrate the high-accuracy of the present system in solar tracking, which are applicable to many existing solar systems.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.7
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• pp.212-217
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• 2020

The PV power generation system is a comprehensive system that transmits the power generated through a PV panel to a grid connection and is composed of a solar panel, a structure, and an inverter grid connection system. One technology to increase the amount of power generated involves changing the incident angle of sunlight. This study examined the structure and control of a single-axis tracking PV system that increases the amount of power generated by changing the incident angle. The core content is a single-axis control system and technology configured to rotate the solar structure in the east-west direction around the north-south axis. A solar structure that follows the sun from sunrise to sunset in the east-west direction needs to secure structural stability and solar tracking control performance. A single-axis tracking system can generate up to 25% more power.

• Korean Journal of Agricultural and Forest Meteorology
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• v.13 no.2
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• pp.79-86
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• 2011

Cold-air drainage and pooling occur in most mountain valleys at night. Local climates with cold-air pooling could affect phenology and distribution of crop plants. A high resolution infrared imaging radiometer was used to visualize the cold-air drainage and thermal belt formation over a small mountainous watershed (ca. $10{\times}5{\times}1$ km for the maximum length${\times}$width${\times}$depth). Thermal images on $640{\times}480$ pixels were scanned across the Akyang valley (south of Mt. Jiri National Park) by the radiometer installed at a local peak ('Hyongjebong', 1,117 m a.s.l.) at dawn of 17 May 2011, when the synoptic condition was favorable for the surface cooling and cold-air drainage. Major findings are: (1) Cold-air drainage and accumulation was clearly identified by the lowest brightness temperature mainly at the valley bottom. (2) So-called 'thermal belt' with higher brightness temperature was found partway up the valley sidewalls and showed up to $5^{\circ}C$ departure from the valley bottom temperature. (3) Digital thermography showed feasibility for validation of the high definition geospatial temperature models currently in use for the plot-specific agrometeorological service.

• Journal of the Korean Applied Science and Technology
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• v.35 no.3
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• pp.683-694
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• 2018

The ginseng extract was dried and added forming agents using lactose, glucose and arabic gum to enhance convenience and consumer acceptability. As the addition of lactose increased, the absorption of ginseng granule decreased and the solubility tended to increase as the amount of glucose added decreased. The amount of solubilized saponin from the ginseng granules was affected more by the addition amount of ginseng concentrate than by the kind and amount of the forming agents added. Absorption and solubility tended to increase with increasing amount of arabic gum, and there was no significant difference in color change(p<0.05). The optimal mixing ratio of ginseng granules according to addition of forming agents was 10% of ginseng concentrate, 80% of lactose, 5% of glucose and 5% of arabic gum.

• 한국태양에너지학회:학술대회논문집
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• 2009.04a
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• pp.31-36
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• 2009

There have been many solar tracking systems developed for the high accuracy in solar tracking. One of the key components of any motion control system is software. LabVIEW offers an ideal combination of flexibility, ease-of-use and well-integration with other I/O pieces for developing solar tracking system. Real-time solar positions which vary with GPS's data are used simultaneously to control the solar tracker by a chain of operating modes between the open and closed loops. This paper introduces a step by step procedure for the fabrication and performance assessment of a precision solar tracking system. The system developed in this study consists of motion controllers, motor drives, step-motors, feedback devices and application. CRD sensors are applied for the solar tracking system which play a primary role in poor conditions for tracking due to a gear backlash and a strong wind. Mini-dish was used as a concentrator for collecting sun light. The solar position data, in terms of azimuth and elevation, sunrise and sunset times was compared with those of KASI(Korea Astronomy & Space Science Institute). The results presented in this paper demonstrate the accuracy of the present system in solar tracking and utilization.

• Korean journal of applied entomology
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• v.30 no.2
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• pp.124-129
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• 1991

This study investigated seasonal occurrence and daily flight activity using synthetic sex pherom mone and injury characteristics of 야et armyworm, Spodoptera exigua in Chonnam area of K Korea in 1990. Male adults were attracted to phermone trap from mid-June to late November w with the peaks at mid-late August, mid-late September and early-mid November in vinyl i house and also were attracted from mid October to late November in field. Primary peak of occurrence in vinyl house was 20 days sooner than field. It seems to have 6 generations a year in C Chonnam region based on the estimation of larval biomass. Daily male flight was active from m midnight to before sunrise with the peak at 4-6 A.M .. In injury characteristics at various host plants, damage was great in early growing stage at below 10 cm of plant height in Allium fistulsum. Chrysanthemum morifolium was damaged at mostly upper part of leaves reaching to m the extent up to 70%. In case of Gypsophila paniculata, plants injured at early growing stage do n not grow and flower normally.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.21 no.3
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• pp.139-144
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• 1988

The vertical distribution of eggs and larvae of anchovy. Engraulis japonica were studied based on ichthyoplankton and the temperature distribution in the southwestern part of the Sea of Japan off Korea during the summer of 1985 and 1986. Thermoclines occurred at the surface layer in the coastal area and at the sub-surface layer in the offshore area in the early summer of 1985. However, they occurred at the surface layer throughout the summer of 1986. Anchovy eggs and larvae were abundant in the offshore in 1985 and in the coastal area in 1986. It seems that the spawning ground of anchovy in 1985 shifted to the offshore owing to the sloping of thermoclines. According to the distribution layer of anchovy eggs by developmental stage, the eggs in the early developmental stage were abundant at $0\~30m$ layer about 06:00. But the eggs in the late developmental stage were abundant at $30\~100m$ loom layer about 24 : 00. These results suggest that anchovy spawn at the $0\~30m$ layer at night and eggs tend to sink to the $30\~100m$ layer in the course of development.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.10 no.3
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• pp.16-24
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• 2011

The vehicle electronic control system is being developed as the legal and social demand for ensuring driver's safety is rising. The various Driver Assistance Systems with various sensors such as radars, camera, and lasers are in practical use because of the falling price of hardware and the high performance of sensor and processer. In the preceding study of this research, the program was developed to recognize the experiment vehicle's driving lane and the cars nearby or approaching the experiment vehicle throughout the images taken by CCD camera. In addition, the 'dangerous driving analysis program' which is Vision System basis was developed to analyze the cause and consequence of dangerous driving. However, the Vision system developed in the previous studyhad poor recognition rate of lane and vehicles at the time of passing a tunnel, sunrise, or sunset. Therefore, through mounting the brightness response algorithm to the Vision System, the present study is aimed to analyze the causes of driver's dangerous driving clearly by improving the recognition rate of lane and vehicle, regardless of when and where it is.

• Journal of the Korean Ceramic Society
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• v.35 no.2
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• pp.137-144
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• 1998

High-temperature superconducting joints between 61 filaments of Bi-2223 tapes were fabricated by chem-ical corrosion and repeated thermomechanical process. The silver sheath of the superconducting tape was chemically removed using chemical etchant(NH4OH:H2O2=1:1) from one side of each tape without altering the form of lap joint. The joined region was formed by uniaxial pressing and a series of thermomechanical process and then subjected to properties measurement and microstructural analysis. The critical current(Ic) variation and I-V characteristics along the joint were mesured with several configuration of proble points. Ic value of the transition region of the joint inthe multifilament tape which limit the total current carring capacity of the superconducting tape was higher than that of monofilament tape. But the transition ex-ponent n-value of the multi-filament tape was lower than that of monofilament wire due to the interaction of the individual superconducting core of the multi-filament. The critical current through the joint area was improved by respeated press and reaction annealing treatment.

• Journal of the Korean Applied Science and Technology
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• v.37 no.1
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• pp.28-37
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• 2020

Ginseng berry contains a large amount of Ginsenoside Re and has anti-inflammatory, anticancer, hypoglycemic and whitening effects. In this study, Rhizopus Oligosporus strain was used to establish ginseng berry fermentation process and cosmetic pharmacological activity of ginseng berry fermented product was analyzed.. The electron donating ability of ginseng berry extract by fermentation shown 81% at 1,000 ㎍/mL concentration. The ABTS⁺ radical scavenging ability of shown 100.2% at 1,000 ㎍/mL concentration. The tyrosinase inhibitory effect which is related to skin-whitening, was 57% at the concentration of 1,000 ㎍/mL. The elastase inhibitory effect which is related to skin-wrinkle, was 47% at 1,000 ㎍/mL concentration. Also, the collagenase inhibition effect was 33% at 1,000 ㎍/mL concentration. From these results, ginseng berry extracts by fermentation is considered to have anti-inflammatory, anti-wrinkle effect and whitening effect. Therefor, ginseng berry fermented product is expected to be very useful as an anti-inflammatory and anti-aging cosmetic raw material.