• The Journal of the Convergence on Culture Technology
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• v.9 no.2
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• pp.575-580
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• 2023

This study was prevent the decrease in crop output by insect pests and spraying by application uniformity. A flight level 4 m height and 4-5 m/sec. speed are difficult to maintain with a agricultural drone for aerial application, which has been affected by the methods or environmental factors, such as changes in the wind. Therefore, which can allow a controlled application width and spray rate automatically and verified experimentally using drone. The sprayed particles began to decrease from about 3.75 m on the left and right sides of the spray nozzle. According to the number of particles, the effective spraying width was observed to be about 7.5 m, and it was verified that the proposed spraying system was effective in uniform control system.

• Korean Journal of Applied Biomechanics
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• v.15 no.4
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• pp.43-53
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• 2005

This study is to define how the difference of athletic change influence on the last regrasp after somersault in Belle movement of parallel bars. For his study, the following conclusion was produced by analysis of athletic change by means of three dimensional visual image in three athlete of nation. 1. As the picture of S1, there are total used time(2.01 sec), S3(2.17 sec) and S2(2.19 sec). In case of a short needed time, it is difficult for them to perform the remaining movement of the vertical elevating flight easily and comfortably, it is judged as performing the small movement with restrict swing. 2 In the change of body center sped by each event, it is calculated as $-89.1^{\circ}$ the narrowest in S1, $-81.96^{\circ}$ the widest and then $86.34^{\circ}$ in S3. In E3 event, average compound speed is 4.07m/s, S2 showed the fastest speed of 4.14m/s whereas S1 the narrowest angle of 3.95m/s. 3. A shoulder joint and coxa are the period of mention in E3. In E4 which was pointed out the longest vertical distance, S2 that is indicated the highest vertical height as the period of detach in parallel bars. showed -3.91m. This is regarded as a preparatory movement for dynamic performance after using effectively elastic movement of shoulder joint and coxa while easily going up with turning back movement. In the 5th phrase, long airborne time and vertical change position is showed as the start while regrasping securely air flight movement from high position. 4. In E5, a long flight time and a long vertical displacement were shown as the regrasp after somersault efficiently in high position with stability from the point of the highest peak of the center of the body. Especially, S2 is marked as a little bit long position, while S1 is reversely indicated as performing somersault and unstable motion in a low position. 5. In E3, at the point of the largest extension of the shoulder joint and hip joint the shoulder joint is largely marked in $182^{\circ}$ and the hip point $182^{\circ}$ in S2. The shoulder joint is marked at the smallest angle in $177^{\circ}$ and the hip point $176^{\circ}$ in S1. And S1 is being judged by its performance of the less self - confident motion with lessening a breath of swing. S2 makes the most use of flexion and extension of the shoulder joint and the hip joint effectively. It was performed greatly with swinging and dropping the rotary movement and the rotary inertia naturally. 6. In E6, as the point of regrasp of the upper arm in parallel bars it is recognized by the that of components of vertical and horizontal velocity stably. During this study, the insufficient thing and the study on the parallel bars at a real game later are more activated than now. If it is really used as the basic materials by means of Belle Picked Study of Super E level after Bell movement, you may perceive the technique movement previously and perform without difficulty. Especially, such technique as crucifix is quite advantageous for oriental people thanks to small body shape condition. In conclusion we will nicely prepare for our suitable environment to gradually lessen trials and errors by analyzing and studying kinematically this movement.

• The Korean Journal of Air & Space Law and Policy
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• v.32 no.1
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• pp.225-285
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• 2017

In regard to the regulations related to the RPA(Remotely Piloted Aircraft), which is sometimes called in other countries as UA(Unmanned Aircraft), ICAO stipulates the regulations in the 'RPAS manual (2015)' in detail based on the 'Chicago Convention' in 1944, and enacts provisions for the Rules of UAS or RPAS. Other contries stipulates them such as the Federal Airline Rules (14 CFR), Public Law (112-95) in the United States, the Air Transport Act, Air Transport Order, Air Transport Authorization Order (through revision in "Regulations to operating Rules on unmanned aerial System") based on EASA Regulation (EC) No.216/2008 in the case of unmanned aircaft under 150kg in Germany, and Civil Aviation Act (CAA 1998), Civil Aviation Act 101 (CASR Part 101) in Australia. Commonly, these laws exclude the model aircraft for leisure purpose and require pilots on the ground, not onboard aricraft, capable of controlling RPA. The laws also require that all managements necessary to operate RPA and pilots safely and efficiently under the structure of the unmanned aircraft system within the scope of the regulations. Each country classifies the RPA as an aircraft less than 25kg. Australia and Germany further break down the RPA at a lower weight. ICAO stipulates all general aviation operations, including commercial operation, in accordance with Annex 6 of the Chicago Convention, and it also applies to RPAs operations. However, passenger transportation using RPAs is excluded. If the operational scope of the RPAs includes the airspace of another country, the special permission of the relevant country shall be required 7 days before the flight date with detail flight plan submitted. In accordance with Federal Aviation Regulation 107 in the United States, a small non-leisure RPA may be operated within line-of-sight of a responsible navigator or observer during the day in the speed range up to 161 km/hr (87 knots) and to the height up to 122 m (400 ft) from surface or water. RPA must yield flight path to other aircraft, and is prohibited to load dangerous materials or to operate more than two RPAs at the same time. In Germany, the regulations on UAS except for leisure and sports provide duty to avoidance of airborne collisions and other provisions related to ground safety and individual privacy. Although commercial UAS of 5 kg or less can be freely operated without approval by relaxing the existing regulatory requirements, all the UAS regardless of the weight must be operated below an altitude of 100 meters with continuous monitoring and pilot control. Australia was the first country to regulate unmanned aircraft in 2001, and its regulations have impacts on the unmanned aircraft laws of ICAO, FAA, and EASA. In order to improve the utiliity of unmanned aircraft which is considered to be low risk, the regulation conditions were relaxed through the revision in 2016 by adding the concept "Excluded RPA". In the case of excluded RPA, it can be operated without special permission even for commercial purpose. Furthermore, disscussions on a new standard manual is being conducted for further flexibility of the current regulations.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.9
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• pp.92-100
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• 2017

The Helicopter MRA Control Rod System has the important function of controlling the speed, height, and direction of helicoptersby adjusting the main rotor disc. However, the ingress of water into the inner control rod can cause ice damage in the rod during winter operation and also corrosion;these defects need to be rectified. The water flowed into the control rod through the upper side space, and the rod was cracked during icing expansion occurring at low temperature. The corrosion occurred due to the lack of coating process during the manufacturing process. To resolve these problems, the upper rod was sealed to prevent water inflow and a coating process was added to prevent corrosion. These solutions were verified by awaterproof test and a salt fog test. The phenomena, causes and measures were reviewed and the methods of improvement were established and proven. This proposed technology to prevent water infiltration and corrosion will contribute to the safety of rotary wing aircraft.

• Journal of Korean Society of Transportation
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• v.23 no.6 s.84
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• pp.41-53
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• 2005

The effective utilization of an airport is considerably influenced by natural features and man-made structures inside and outside its boundary. These obstacles affect the airspace available for approaches and departures and the weather minima which dictates the necessary weather conditions for aircraft to be allowed to take-off or land. Certain areas of the airspace near airports must be regarded as the integral parts of the airport system. The availability of the required airspace is as important as are the runway and their associated strips to the safe and efficient use of the airport. For these reasons, ICAO and the member states have established the standards regarding the obstacle limitation surfaces and regulated the construction of the man-made structures in and beyond the surfaces. Existing objects that extend above a obstacle limitation surfaces should as for as practicable be removed except when, in the opinion of the appropriate authority, an objects is shielded an existing immovable objects, or after aeronautical study it is determined that the object would not adversely affect the safety or significantly affect the regularity of operations of airplanes. However, Korea's aviation law does not specified the outer horizontal surface in the obstacle limitation surfaces, while ICAO and most member states do. The absence of the outer horizontal surface regulation has created legal disputes between regulating agencies and private parties. The case study in this paper found that a skyscraper planned beyond Korea's obstacle limitation surfaces does affect the flight safety and the efficient use of an airport. Therefore, in areas beyond the obstacle limitation surfaces. those objects which extend to a height of 150m or more above ground elevation should be regarded as obstacle, unless a special aeronautical study indicates that they do not constitute a hazard to airplanes. We proposed low alternative regulatory schemes for resolving the issues raised in this paper, and we recommended to adopt ICAO's standards and recommended practices.

• Journal of the Korean Vacuum Society
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• v.12 no.1
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• pp.55-63
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• 2003

A 150 kV gas cluster ion accelerator was constructed and the cluster sizes of $CO_2$ and $N_2O$ gases were measured using time-of-flight mast spectrometry. Through isolated cluster ion impact on a HOPG, hillock with 1 nm height and a few tenth m in diameter were found to be formed by an atomic force microscope. When monomer ion beams were irradiated on the hillocks existed on a ITO surface, they became sharper and the surface became rougher. But they changed into round-shaped ones by cluster ion irradiation and the surface became smooth after the irradiation of $5\times10^{-14}\textrm{cm}^2$ at 25 kV. As the cluster ion dose was varied, the change of surface morphology and roughness of Si was examined. At the lower dose, the density of hillocks and surface roughness were increased, called surface embossment process. And then after the critical dose at which the area of the formed hillocks equals to the unirradiated area, the sputtering from the hillocks was predominantly evolved, and dislocated atoms were diffused and filled among the valleys, called surface sputtering and smoothing process. At the higher ion dose, the surface consisting of loosely bounded atoms was effectively sputtered into the depth and etching phenomenon was happened, called surface etching process.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.5
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• pp.682-692
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• 2007

This study presents an automatic system to predict parturition time in the crated sows. The system relies on ultrasonic transducers mounted from above along the length of the crate. Using a 40 kHz time of flight (TOF) single envelope wave, the momentary distances between the sensors are measured. Therefore, the local momentary height of the sow and the momentary posture, i.e. standing posture (SDP), kneeling posture (KP), sitting posture (STP) and lateral lying posture (LLP) are determined. Crated sows change their postures from standing to lying and vice versa which follows a characteristic pattern. As parturition approaches, sows exhibit uneasiness, restlessness and the stand up sequence (SUS, the posture transition from LLP to SDP) rate increases because of labor pains. In time series, the SUS rate demonstrates a peak and it happens approximately 0-12 h before parturition. In this paper, the basic parturition threshold value method (BPTVM) and the same hour method (SHM) are proposed for predicting parturition, both of which are based on the SUS rate. The BPTVM mainly detects the peak of the SUS rate. As the SUS rate exceeds the threshold value, the parturition becomes predictable. Moreover, the SHM calculates the difference in the SUS rates between a particular time of day and the corresponding time of the preceding day. Compared to the BPTVM, the SHM can eliminate the circadian rhythm of the SUS rate influenced by feeding behavior. Using the SHM the parturition can be approximately predicted within hours. In an attempt to define the threshold parameters of predicting parturition, a data set with 32 sows of the SUS rate are used to estimate assumable predicting probability. The results show the assumable probability of the parturition prediction within 9 h is 96.9% for the SHM and 84.4% for the BPTVM. Moreover, the SHM can even reach a 75% probability of prediction within three hours of parturition. We conclude that the SHM is more accurate and is more useful for parturition time prediction. When parturition is detected, the proposed algorithm generates a warning signal which can inform human personnel to protect the mother and newborn piglets.

• Journal of Korean Society for Atmospheric Environment
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• v.33 no.4
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• pp.411-423
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• 2017

The spacial potential source contribution function (PSCF) method was utilized by considering topography and height of back trajectories based on the measurement of organic typo matter (OM), $NO_3{^-}$, $SO{_4}^{2-}$, and $NH_4{^+}$ at the Baegryungdo Super Site ($37^{\circ}57^{\prime}N$, $124^{\circ}37^{\prime}E$, 135 m a.s.l. (above sea level)) for three selected periods (i.e., January~April, May~August, and September~December) in 2013. The PSCF were calculated on the contributions of trans-boundary transport to the hourly mean concentrations using a high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS). The cluster analysis using back trajectories was performed to identify the major airflows to the sampling site. The upper atmosphere in the Tianjin area of China and the lower atmosphere in the western coast area of Korea can be the major source of trans-boundary pollution to the sampling site during January~April resulted from PSCF. The area in Lianyungang-city and Liaoning-sheng, China can be responsibile for the nitrogen related secondary compounds during May~August, and Shandong Peninsula in China is the major source area during September~December. In addition, relationships between the cluster analysis of back trajectories and PSCF were investigated for the statistically significance level for the source areas.

• Tunnel and Underground Space
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• v.26 no.1
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• pp.24-31
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• 2016

Recently, many studies have been conducted to use fixed-wing and rotary-wing unmanned aerial vehicles (UAVs, Drones) for topographic surveying in open-pit mines. Because the fixed-wing and rotary-wing UAVs have different characteristics such as flight height, speed, time and performance of mounted cameras, their results of topographic surveying at a same site need to be compared. This study selected a construction site in Yangsan-si, Gyeongsangnam-do, Korea as a study area and compared the topographic surveying results from a fixed-wing UAV (SenseFly eBee) and a popular rotary-wing UAV (DJI Phantom2 Vision+). As results of data processing for aerial photos taken from eBee and Phantom2 Vision+, orthomosaic images and digital surface models with about 4 cm grid spacing could be generated. Comparisons of the X, Y, Z-coordinates of 7 ground control points measured by differential global positioning system and those determined by eBee and Phantom2 Vision+ revealed that the root mean squared errors of X, Y, Z-coordinates were around 10 cm, respectively.

• Spatial Information Research
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• v.17 no.3
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• pp.397-404
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• 2009

To solve the problems of distribution and quality on land gravity data, airborne gravity survey was performed in 2008 obtaining the airborne gravity data with accuracy of 1.56mGal. Since airborne gravity data is the obtained at the flight height, it is necessary to convert the airborne gravity data to the surface to combine various gravity data and compute precision geoid. In addition, Stokes' integral radius, Stokes' kernel and the radius of terrain effect computation should be optimally determined to calculate precision geoid. In this study, we made an effort to decide the optimal parameters based on the distribution and the characteristic of gravity data. Then, two geoid models were calculated using the selected parameters and the difference of geoid was calculated with mean of -16.95cm and the standard deviation of ${\pm}8.50cm$. We consider that this difference is due to the distribution and errors on the gravity data. For future work, the study on the effect of geoid with newly obtained land gravity data ship-borne gravity data and GPS/Leveling data should be conducted. Furthermore, the study on the downward continuation and terran effect calculation should be studied in detail for better precision geoid construction.