• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.33 no.2
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• pp.73-81
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• 2015

The objective of this study is in investigating the research for more accurately quantify the information on mountain forest by using the data on high density LiDAR. For the quantitative analysis of mountain forest resources, we investigated the method to acquire the data on high density LiDAR and extract mountain forest resources. Consequently, the height and girth of a tree each mountain forest resources could be extracted by using the data on high density LiDAR. When using the data on low density LiDAR of 2.5points/m² in average used to produce digital map, it was difficult to extract the exact height and girth of mountain forest resources. If using the data on high density LiDAR of 7points/m² by considering topography, the property of mountain forest resources, data capacity and process velocity, etc, it was found that multitudinous entities could be extracted. It was found that mountain topography and mixed topography were generally denser than plane topography and multitudinous mountain forest resources could be extracted. Furthermore, it was also found that the entity at the border could not be extracted, when each partition was individually processed and the area should be subdivided and extracted by considering the process time and property of target area rather than processing wide area at once. We expect to be studied more profoundly the absorption quantity of greenhouse gas later by using information on mountain forest resources in the future.

• Journal of Korean Society of Transportation
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• v.23 no.4 s.82
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• pp.17-28
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• 2005

About 91.1% of Railway-Highway Crossings (RHC) in Korea use a Constant Distance Warning System(CDWS), while about 8.9% use a Constant Warning Time System(CWTS). The CDWS does not recognize speed differences of approaching trains and provides only waiting times to vehicles and pedestrians based on the highest speed of approaching trains. Under the CDWS, therefore, low speed trains provide unnecessary waiting times at crossings which often generates complains to vehicle drivers and pedestrians and may cause wrong decisions to pass the crossings. The objective of this research is to improve the safety of the RHC by developing accurate a CWTS. In this research a train speed and location detection system was developed with ultra sonic detectors. Locations of the detectors was decided based on the highest speed and the minimum warning time of Saemaul of 160 km/h. To validate the algorithms of the newly developed systems the lab tests were conducted. The results show that the train detection system provides accurate locations of trains and the maximum error between real speeds of trains and those of the system was 0.07m/s.

• Journal of the Korean Vacuum Society
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• v.22 no.3
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• pp.111-118
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• 2013

The influence of gas flow on the plasma generation in the atmospheric plasma jet is described with the theory of hydrodynamics. The plasma discharge is affected by the gas-flow streams with Reynolds number (Re) as well as the gas pressure with Bernoulli's theorem according to the gas flow rate inserted into the glass tube. The length of plasma column is varied with the flow types such as the laminar flow of Re<2,000 and the turbulent flow of Re>4,000 as it has been known in a general fluid experiments. In the laminar flow, the plasma column length is increased as the increase of flow rate. Since the pressure in the glass tube becomes low as the increase of flow velocity by the Bernoulli's theorem, the breakdown voltage of plasma discharge is reduced by the Paschen's law. Therefore, the plasma length is increased as the increasing flow rate with the fixed operation voltage. In the transition of laminar and turbulent flows, the plasma length is decreased. When the flow becomes turbulent as the flow rate is increasing, the plasma length becomes short and the discharge is shut down ultimately. In the discharge of laminar flow, the diameter of plasma beam exposed on the substrate surface is kept less than the glass diameter, since the gas flow is kept to the distinct distance from the nozzle of glass tube.

• Journal of Oriental Medical Thermology
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• v.6 no.1
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• pp.23-31
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• 2008

Objective: The purpose of this study is to identify relationship between the PWV and the temperature difference. Methods: When it comes to senile patients who suffer from cold limbs, there is need to see whether or not the patient's low temperature of the limbs is do to arteriosclerosis. The Pulse Wave Velocity(PWV) is a non-invasive method measuring the artery's rigidness. And the Digital Infrared Thermal Imaging(D.I.T.I) is a non-invasive method to see the body's thermal change. Research on the interrelationship of the artery's rigidness and body's thermal distribution was done by using these two tests. The subjects of this research were patients between the age 40~65 who have done both the D.I.T.I and PWV in March 2005~ September 2005. They had to have no history of diabetes, coronary illnesses or cerebrovascular diseases which are diseases that can effect the outcome of the PVW, nor history of spondylopathy or dermatosis which can effect the outcome of the D.I.T.I. Results: The results were as follows. 1. There was a significant interrelationship between the right wrist-ankle PWV and the temperature difference of the right wrist-palm. 2. There was a significant interrelationship between the left wrist-ankle PWV and the temperature difference of the left wrist-palm. 3. There was no significant interrelationship between the right wrist-ankle PWV and the temperature difference of the right thigh-dorsum of foot. 4. There was no significant interrelationship between the left wrist-ankle PWV and the temperature difference of the left thigh-dorsum of foot. 5. The right ABI showed no significant interrelationship between the temperature difference of the right wrist-palm and the right thigh-dorsum of foot. 6. The left ABI showed no significant interrelationship between the temperature difference of the left wrist-palm and the left thigh-dorsum of foot. Conclusion: The study shows that there was a significant interrelationship between wrist-ankle PWV and the temperature difference of wrist-palm.

• Journal of Conservation Science
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• v.26 no.3
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• pp.277-294
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• 2010

The Seosanmaaesamjonbulsang (National Treasure No. 84) consists of light gray and coarse to mediumgrained biotite granite with partly developed pegmatite and quartz vein. The host rock is divided into dozens of rock blocks with various shape along irregular discontinuity plane. The evaluation results of discontinuity systems reveal that the host rock were exposed to instable sloping environments. Results of deterioration diagnosis show that the degree of damage has been made worse by physical weathering and surface discoloration laying stress on part that vertical and horizontal joints are massed. Generally, deterioration rate of the triad Buddha surface cover with 42.7%, however, the rate of physical weathering and surface discoloration are subdivided to 9.6% and 33.1%, respectively. Ultrasonic measurements indicate that the triad Buddha was reached highly weathered grade in general. And the rock material was weaken to show low velocity zone of 1,000m/s along irregular joint systems. Indoor and outdoor mean relative humidity of the shelter was recorded more than 70% during every season, and high frequency appears in high relative humidity range over 95%. Such environments seem to have produced dew condensation on the rock surface with rainfall and supply water, promoted physical, chemical and biological weathering along crack and joint, resulting in high permeation of water and percentage of water content. Therefore, it is judged that for scientific conservation of the triad Buddha it needs environment control through persistent preservation environment monitoring including water problem.

• Journal of the Korea Concrete Institute
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• v.28 no.5
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• pp.593-600
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• 2016

The paper presented investigates the effects of kaolinite on strength properties of alkali-activated multi-component cement. The binders of this study was blended of ground granulated blast furnace slag (GGBFS), fly ash (FA), silica fume (SF) and kaolinite (KA). In this study, the specimens of combination of 20%~70% GGBFS, 10%~60% FA, 10% SF (constant ratio) and 10%~50% KA binder were used for strength properties tests. The water/binder ratio was 0.5. The binders (GGBFS + FA + SF + KA) was activated by sodium hydroxide (NaOH) and sodium silicate ($Na_2SiO_3$) was 10% by total binder weight (10% NaOH + 10% $Na_2SiO_3$). The research carried out is on the compressive strength, water absorption, ultrasonic pulse velocity (UPV) and X-ray diffraction (XRD). The compressive strength decreased as the contents of KA increase. One of the major reason for this is the low reactivity of KA compared with other raw materials used as precursors such as GGBFS or FA. The presence of remaining KA indicates that the initially used quantity has not fully reacted during hydration. Moreover, the results have indicated that increased of KA contents decreased UPV under all experimental conditions. The drying shrinkage and water absorption increased as the content of KA increase. Test result clearly showed that the strength development of multi-component blended cement were significantly dependent on the content of KA and GGBFS.

• Journal of the Korean earth science society
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• v.34 no.6
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• pp.575-587
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• 2013

DC electrical and electromagnetic survey was applied to evaluate the reserve of an iron mine site. We analyzed the borehole cores and the cores sampled from outcrops in order to decide which geophysical method was efficient for the evaluation of iron mine site and to understand the geological setting around the target area. Based on the core tests for specific weight, density, porosity, resistivity and P-wave velocity, showing that the magnetite could be distinguishable by the electrical property, we decided to conduct the electrical survey to investigate the irone mine site. According to previous studies, the DC electrical survey was known to have various arrays with high resolutions effective to the survey of the iron mine site. However it was also known that the skin depth is too shallow to grasp the deep structure of iron mine. To compensate the weakness of the DC electrical method, we applied the MagnetoTelluric (MT) survey. In addition, a Controlled Source MT (CSMT) method was also applied to make up the shortcoming of MT method which is weak for shallow targets. From the DC electrical and MT survey, we found a new low resistivity zone, which is believed to be a magnetite reserve beneath the old abandoned mine. Therefore, this study was confirmed for additional utility value.

• Annals of Clinical Neurophysiology
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• v.11 no.2
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• pp.41-47
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• 2009

Background: Discogenic pain can develop into chronic low back pain that is very difficult to treat effectively, because the pathogenesis of the disease still remains controversial. To clarify the pathogenesis, numerous animal models of intervertebral disc degeneration have been proposed in the literature, each with attendant advantages and disadvantages. The aim of this study was to determine the most efficacious method and dose of complete Freund's adjuvant (CFA) injection into intervertebral disc to develop a discogenic pain in a rat. Methods: CFA was injected into the L5-L6 or L4-L5 disc of male Sprague-Dawley rats in various conditions including a dose of CFA (10, 20, or 50 uL), drilling, injection site sealing using cyanoacrylate, and injection velocity. Sham animals were subjected to the same procedure, except for the CFA injection. Mechanical and heat allodynia were serially measured at both hindpaws until 8 weeks post-operatively. Serial MRI analyses were performed to observe degenerative changes of the discs. In addition, CGRP & Substance P-immunoreactivities (ir) in the superficial dorsal horn were evaluated at 4 weeks using immunohistochemistry. Results: Each condition provoked various problems such as development of hindpaw paralysis, CFA leakage, and no pain development. Mid-sagittal T2 MRI revealed no significant degenerative changes in the CFA injected disc. The CGRP-ir of the bilateral superficial dorsal horns at the level of L5-L6 was significantly increased in the CFA group. Conclusions: A total of 10 uL CFA injection into L5-L6 disc for a period of 10 minutes using a 26-gauge needle without drilling was the most efficacious way to develop discogenic pain animal model.

• Economic and Environmental Geology
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• v.36 no.2
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• pp.123-131
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• 2003

Geophysical surveys(electrical resistivity, self-potential, seismic refraction, GPR) were conducted to investigate the physical properties of the subsurface, and to delineate the flow channel of leachate from a AMD(acid mine drainage), buried rock wastes and tailings, and drainage pipes at an abandoned mine(Kwangyang mine). Especially in rainy season the sites appear to be abundant in AMD leachate, characterized by electrical conductivities of 0.98-1.10 ms/S. Electrical resistivity sections indicate that the leachate flows running in two directions at southern part rise up through the narrow fracture zones at the central part and contaminates the surrounding soil and stream. Such schematic features at the anomalous zone are well correlated with negative peaks in self-potential data, the limited penetration depth in GPR data and low velocity zone in seismic refraction data. Shallow high-resistivity zone is associated with the buried rock wastes which cause the diffractions in GPR image. In addition, the events at depth of approximately 1-1.25 m in GPR sections must be the metal pipes through which AMD is drained off to the inner bay.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.30 no.8
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• pp.120-125
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• 2002

In the preceding tests using the KSR-III Sub.(I) engines, it was observed that the heat resistant capability of the engines was not enough for the mission. So Sub.(I) Mod. engines were designed and tested. The Sub.(I) Mod. engines have three major design parameters - the arrangement of main injectors, the impinging angle of main injectors and thermal barrier coating. More than twenty experiments were carried on to evaluate engine performance and heat resistance capability with respect to design parameters. In this study, the test results are introduced. Analysing the result of Sub.(I) engine tests, it is found that decreasing the impinging angle, adopting the H-type arrangement(rather than radial type arrangement) and adopting the thermal barrier coating can increase heat resistance capacity substantially. Also, engine performance evaluation is conducted using specific impulse and characteristic velocity parameter. The results show that the performance variation is small(about 5%) and the performance is better in the case of radial arrangement. It is suspected that these phenomena are caused by the change of flame structure atomization mixing characteristic of sprays and the distortion of recirculation zone. Also from the low frequency instability point of view, it is observed that reducing the impinging angle and adopting the H type arrangement can increase the instability characteristics.