• Journal of the Korean Geographical Society
• /
• v.45 no.1
• /
• pp.184-200
• /
• 2010

The production period of Daedongyeojijeondo is estimated from 1861 to 1866 in consideration of place names. Daedongyeojijeondo is elaborated enough that there are the latest data in, especially is better than Haejwajeondo that is a representative map in the 19th century in marking distance. Daedongyeojido is an official map for national defense and administration, on the other hand Daedongyeojijeondo is a popular map in which social and economical contents are included. The recognition of mountains and rivers based on organic view of the land is also represented in Daedongyeojijeondo, and the principle of the whole of mountains and rivers is well reflected. It is far better than modem maps in the expression of road system and distances, tidal area in rivers.

• Journal of information and communication convergence engineering
• /
• v.21 no.3
• /
• pp.252-260
• /
• 2023

A bullet launcher can be developed as a smart instrument, especially for use in the military section, that can track, identify, detect, mark, lock, and shoot a target by implementing an image-processing system. In this research, the application of object recognition system, laser encoding as a unique marker, 2-dimensional movement, and pneumatic as a shooter has been studied intensively. The results showed that object recognition system could detect various colors, patterns, sizes, and laser blinking. Measuring the average error value of the object distance by using the camera is ±4, ±5, and ±6% for circle, square and triangle form respectively. Meanwhile, the average accuracy of shots on objects is 95.24% and 85.71% in indoor and outdoor conditions respectively. Here, the average prototype response time is 1.11 s. Moreover, the highest accuracy rate of shooting results at 50 cm was obtained 98.32%.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.48 no.5
• /
• pp.760-767
• /
• 2015

First annulus formation and age determination of otoliths were examined for chub mackerel Scomber japonicus collected in Korean waters over the one year from January to December in 2009. Translucent zone was regarded as an annual mark. Age interpretation criteria was based on the data of the number of translucent zone, capture date, and edge type of the otolith, assuming the nominal birthday to be 1 January. Monthly changes in mean marginal index indicated that translucent zone was formed once a year, mainly in June. The otolith of 0-ring group was detected comparing the progression by month of the smaller fish length, appearing to be a single first opaque zone. The average distance from the core to the first translucent zone was ~1.77 mm, provided as supplementary information to increase ageing accuracy. The ageing criteria for chub mackerel was made to determine correct year-class with the purpose of effective stock assessment. This method using nominal birthdate and edge type analysis could estimate age of fish closer to the true age than purely counting the number of translucent zone on a whole otolith.

• Nuclear Engineering and Technology
• /
• v.53 no.4
• /
• pp.1266-1276
• /
• 2021

The mask parameters of a coded aperture are critical design features when optimizing the performance of a gamma-ray camera. In this paper, experiments and Monte Carlo simulations were performed to derive the minimum detectable activity (MDA) when one seeks a real-time imaging capability. First, the impact of the thickness of the modified uniformly redundant array (MURA) mask on the image quality is quantified, and the imaging of point, line, and surface radiation sources is demonstrated using both cross-correlation (CC) and maximum likelihood expectation maximization (MLEM) methods. Second, the minimum detectable activity is also derived for real-time imaging by altering the factors used in the image quality assessment, consisting of the peak-to-noise ratio (PSNR), the normalized mean square error (NMSE), the spatial resolution (full width at half maximum; FWHM), and the structural similarity (SSIM), all evaluated as a function of energy and mask thickness. Sufficiently sharp images were reconstructed when the mask thickness was approximately 2 cm for a source energy between 30 keV and 1.5 MeV and the minimum detectable activity for real-time imaging was 23.7 MBq at 1 m distance for a 1 s collection time.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
• /
• 2009.04a
• /
• pp.119-123
• /
• 2009

In the areas of civil engineering or cadastral surveying, multi-orientation process such as setting out boundary mark is regarded as one of the important tasks, measuring land feature and indicating acquired data to the grounds. In case of using dual frequency receiver and TS(total station), there are much advantages in setting out surveying results in the field. However, it costs very expensive and the equipments for enhancing correctness are very complex. In this study, technical factor was reviewed in which single frequence receiver and TS, comparatively cheap and easy to establish a system, was connected into TS(Total Station) in order to make easy to orientation and setting out. As a result of this study, it was possible to support GPS and TS surveying and set out it by short distance wireless communication method using single frequency GPS receiver. And by developing the system, it also could lessen the time of setting out in large areas and difficulty of the surveyors in the field.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.31 no.1D
• /
• pp.65-72
• /
• 2011

When an expressway intersects another expressway, a unique connector needs to be designed between the two consecutive exit ramps. In such a case, it is important to design a connector such that there is enough distance for drivers to find their way safely. A current design manual in Korea prescribes the minimum length of the connector as 240 m. In this research, we have suggested a method for calculating the minimum length of a connector in order to check the feasibility of the currently prescribed length. For this purpose, we have attempted to determine the total perception-reaction time and lane-changing time required by a driver. For determining the driver's perception-reaction time, we have used the driver's decision time in addition to the conventional 2.5 s of perception-reaction time for stopping sight distances. We have considered both the design speed and the average travel speed for the calculation of the length. To evaluate the accuracy of the new method, we have chosen four sites on expressways for which relatively high accident rates were recorded. As a result, we could verify that the current limit (240 m) was sufficient for drivers to be able to change lanes in the given specific geometry. However, the prescribed limit should be revised in case the drivers' decision time is considered to be their perception-reaction time. All new approaches for calculating the ideal length of a connector have been carried out by taking into account the design speed as well as the average travel speed. Owing to the characteristics of the specific geometry for two consecutive exit ramps and the large difference between the design speed and the average travel speed in the objective areas, it is more realistic to use the proposed method by keeping the decision time equal to a driver's perception-reaction time, in order to determine the ideal distance that should be maintained between two consecutive exit ramps.

• 제어로봇시스템학회:학술대회논문집
• /
• 2005.06a
• /
• pp.535-538
• /
• 2005

Today, most fixed-wing aircrafts are equipped with the antiskid brake system. It can modulate braking moments in the wheels optimally, when an aircraft is landing. So it can reduce landing distance and increase safeties. The antiskid brake system for an aircraft are mainly composed of braking moment modulators (hydraulic control valves) and brake control unit. In this paper, a Mark IV type - fully digital - brake controller is studied. For the development of its control algorithms, a 5-DOF (Degree of Freedom) aircraft landing model is composed in the form of matlab/simulink model at first. Then, braking moment control algorithms using wheel decelerations and slips are made. The developed algorithms are tested in software simulations using state-flow toolboxes in matlab/simulink model. Also, a real-time simulation systems are made, which use hydraulic brake systems of a real aircraft, pressure control valves and its controller as hardware components of HIL(Hardware In-the-Loop) simulation. Algorithms tested in software simulations are coded into the controller and the real-time landing simulations are made in very severe road conditions. The real-time simulation results are presented.

• Parasites, Hosts and Diseases
• /
• v.40 no.3
• /
• pp.139-148
• /
• 2002

In order to study the range of flight and feeding activity of Anopheles sinensis, the dispersal experiment was conducted in Paju city, located in the northern part of Gyeonggi-do, Republic of Korea, during the period of 7th to 28th September 1998. Unfed females An. sinensis were collected in cowshed and released after being marked with fluorescent dye at 23:00 hours on the same day. Released female mosquitoes were recaptured everyday during 21 days using light traps, which were set at 10 sites in the cowsheds located 1, 3, 6, 9 and 12 km north-northwest and north-northeast and at 3 sites located 1, 6 and 9 km toward south-west from the release point. In addition, to study the longest flight distance in one night, we set the light traps at 16 and 20 km toward north-northeast from the release site. All the collected mosquitoes were placed on filter papers and observed on UV transilluminator after treatment with one drop of 100% ethanol. Out of 12,773 females of An. sinensis released, 194 marked females mosquitoes were recaptured, giving 1.52% recapture rate. Of 194, 72 mosquitoes (37 1%) were recaptured in light traps from three places set at 1 km from the release point, 57 mosquitoes (29.4%) from two places at 1-3 km, 41 mosquitoes (21.1%) from three places at 3-6 km, 20 mosquitoes (10.3%) from three places at 6-9 km, and 4 mosquitoes (2.1%) from two places at 9-12 km. Since 170 female mosquitoes (87.6%) out of 194 marked mosquitoes were captured within 6 km from the release point, this flight radius represents the main activity area. An. sinensis was found to be able to fly at least 12 km during one night.

• Korean Journal of Environment and Ecology
• /
• v.37 no.5
• /
• pp.337-346
• /
• 2023

Although wildlife bridge are built as a way to reduce habitat fragmentation caused by road construction, there is still a lot of debate about their effectiveness. Monitoring methods such as footprint traps and camera traps are used evaluate the effectiveness of wildlife bridge, but there is a limit to evaluate of effectiveness. In this study, the degree of use the wildlfe bridge was surveyed by striped field mouse that is likely use the wildlife bridge and surrounding as a habitat with capture-mark-recapture method.(Apodemus agraius). The distance and route of movement were identified by connecting the capture points, and the environmental factors on the use of the wildlife bridge implemented a generalized linear model(GLM) with the capture number of captured as a dependent variable. Consequently of capture, no individuals crossing the wildlife bridge, striped field mouse use the wildlife bridge as a habitat.The environmental factors affecting the use of mice were vegetation cover(1~2m, 2~8m, over 8m), vegetation construction, maximum diameter at breast height were positively correlated and slope was nagatively correlated. In conclusion, it is expected that the effectiveness of the wildlife bridge will be further improved by planting shrubs and trees and preventing high slope and cut slope increasing the utilization of the rat, such as being used as a food source in the ecosystem.

• Journal of the Institute of Convergence Signal Processing
• /
• v.14 no.4
• /
• pp.261-269
• /
• 2013

This paper describes the design and development of VSI (VLBI standard interface) optical adapter for transmitting VLBI(Very long baseline interferometry) observation data with optical signal. VSI cable comprised of 80-line is being used for observed data transmission with maximum length of 5-meter between playbacks (Mark5B, VERA2000) and raw VLBI data buffer (RVDB), RVDB and VLBI correlation subsystem (VCS) in Daejeon correlator. It has a plan to conduct the data processing for 16-stations and introduce the 14 RVDB systems in near future. And data loss frequently occurred because of trouble of VSI cable MDR80 connector. By considering the data loss by connector error of VSI cable, RVDB system extension plan, effective space usage and long distance data transmission(e-VLBI), the VSI optical adapter was proposed and developed for effectively transmitting and receiving VLBI data through optical signal. In order to confirming the performance of developed VSI optical adapter, the experiments for data transmission was conducted between playback and RVDB system, and confirmed that data transmission was clearly done without any data loss.