• Korean Journal of Remote Sensing
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• v.30 no.4
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• pp.455-464
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• 2014

After launching the Geostationary Ocean Color Imager (GOCI) on June 2010, field campaigns were performed routinely around Korean peninsula to collect in-situ data for calibration and validation. Key measurements in the campaigns are radiometric ones with field radiometers such as Analytical Spectral Devices FieldSpec3 or TriOS RAMSES. The field radiometers must be regularly calibrated. We, in the paper, introduce the optical laboratory built in KOSC and the relative calibration method for in-situ measurement spectroradiometer. The laboratory is equipped with a 20-inch integrating sphere (USS-2000S, LabSphere) in 98% uniformity, a reference spectrometer (MCPD9800, Photal) covering wavelengths from 360 nm to 1100 nm with 1.6 nm spectral resolution, and an optical table ($3600{\times}1500{\times}800mm^3$) having a flatness of ${\pm}0.1mm$. Under constant temperature and humidity maintainance in the room, the reference spectrometer and the in-situ measurement instrument are checked with the same light source in the same distance. From the test of FieldSpec3, we figured out a slight difference among in-situ instruments in blue band range, and also confirmed the sensor spectral performance was changed about 4.41% during 1 year. These results show that the regular calibrations are needed to maintain the field measurement accuracy and thus GOCI data reliability.

• Applied Microscopy
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• v.35 no.1
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• pp.31-39
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• 2005

Synapses are contact points where one neuron communicates with another. The morphological change of synapses under various physiological or pathological conditions has long been hypothesized to modify their functional properties. 3-dimensional (3-D) reconstruction of synapses with serial ultrathin sections has contributed to the understanding of ultrastructural dimensions and compositions of synapses. The 3-D reconstruction procedures, however, require a great amount of expertise as well as include prohibitively timeconsuming processes. Here, we introduce efficient 3-D reconstruction technique using high-voltage electron microscopy (HVEM). Primarily, we established an optimal section thickness and staining condition to observe synaptic structures in detail under HVEM. The result showed that synaptic profiles were preserved at the section thickness of 250 nm without the overlapping of synaptic ultrastructures. An increase in the reaction time of en bloc staining was most efficient to enhance contrast than the extension of postembedding staining or the addition of uranyl acetate during dehydration. Then, 3-D reconstruction of parallel fiber-Purkinje cell synapses in the rat cerebellum was carried out with serial HVEM images and reconstruction software. The images were aligned and the contours of synapses were outlined on each section. 3-D synapses were finally extracted from the section files by grouping all the synaptic contours. The reconstructed synapse model clearly demonstrated the configuration of pre and postsynaptic components. These results suggest that 3-D reconstruction of synapses using HVEM is much efficient and suitable for massive quantitative studies on synaptic connectivity than conventional TEM approach using numerous ultrathin sections.

• Journal of Biomedical Engineering Research
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• v.25 no.4
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• pp.261-268
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• 2004

Osteoporosis is a clinical condition in which the amount of bone tissue is reduced and the likelihood of fracture is increased. It is known that the electrical property of the bone is related to its density, and, in particular, the electrical resistance of the bone decreases as the bone loss increases. This implies that the electrical property of bone may be an useful parameter to diagnose osteoporosis, provided that it can be readily measured. The study attempted to evaluate the electrical conductivity of bone using a technique of electrical impedance tomography (EIT). It nay not be easy in general to get an EIT for the bone due to the big difference (an order of 2) of electrical properties between the bone and the surrounding soft tissue. In the present study, we took an adaptive mesh regeneration technique originally developed for the detection of two phase boundaries and modified it to be able to reconstruct the electrical conductivity inside the boundary provided that the geometry of the boundary was given. Numerical simulation was carried out for a tibia phantom, circular cylindrical phantom (radius of 40 mm) inside of which there is an ellipsoidal homeogenous tibia bone (short and long radius are 17 mm and 15 mm, respectively) surrounded by the soft tissue. The bone was located in the 15 mm above from the center of the circular cross section of the phantom. The electrical conductivity of the soft tissue was set to be 4 mS/cm and varies from 0.01 to 1 ms/cm for the bone. The simulation considered measurement errors in order to look into its effects. The simulated results showed that, if the measurement error was maintained less than 5 %, the reconstructed electrical conductivity of the bone was within 10 % errors. The accuracy increased with the electrical conductivity of the bone, as expected. This indicates that the present technique provides more accurate information for osteoporotic bones. It should be noted that tile simulation is based on a simple two phase image for the bone and the surrounding soft tissue when its anatomical information is provided. Nevertheless, the study indicates the possibility that the EIT technique may be used as a new means to detect the bone loss leading to osteoporotic fractures.

• Radiation Oncology Journal
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• v.21 no.4
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• pp.291-298
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• 2003

Purpose: We report upon a web-based system for Patterns of Care Study (PCS) devised for Korean radiation oncology. This PCS was designed to establish standard tools for clinical quality assurance, to determine basic parameters for radiation oncology processes, to offer a solid system for cooperative clinical studies and a useful standard database for comparisons with other national databases. Materials and Methods: The system consisted of a main server with two back-ups in other locations. The program uses a Linux operating system and a MySQL database. Cancers with high frequencies in radiotherapy departments in Korea from 1998 to 1999 were chosen to have a developmental priority. Results: The web-based clinical PCS .system for radiotherapy in www.pcs.re.kr was developed in early 2003 for cancers of the breast, rectum, esophagus, larynx and lung, and for brain metastasis. The total number of PCS study items exceeded one thousand. Our PCS system features user-friendliness, double entry checking, data security, encryption, hard disc mirroring, double back-up, and statistical analysis. Alphanumeric data can be input as well as image data. In addition, programs were constructed for IRB submission, random sampling of data, and departmental structure. Conclusion: For the first time in the field of PCS, we have developed a web-based system and associated working programs. With this system, we can gather sample data in a short period and thus save, cost, effort and time. Data audits should be peformed to validate input data. We propose that this system should be considered as a standard method for PCS or similar types of data collection systems.

• Progress in Medical Physics
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• v.18 no.1
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• pp.1-6
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• 2007

A system to non-invasively fix and monitor eye by a head mounted display (HMD) with a CCD camera for stereotactic radiotherapy (SRS) of uveal melanoma has been developed and implemented clinically. The eye fixing and monitoring system consists of a HMD showing patient a screen for fixing eyeball, a CCD camera monitoring patient's eyeball, and an immobilization mask. At flrst, patient's head was immobilized with a mask. Then, patient was Instructed to wear HMD, to which CCD camera was attached, on the mask and see the given reference point on its screen. While patient stared at the given point in order to fix eyeball, the camera monitored Its motion. Four volunteers and one patient of uveal melanoma for SRS came into this study. For the volunteers, setup errors and the motion of eyeball were analyzed. For the patient, CT scans were peformed, with patient's wearing HMD and fixing the eye to the given point. To treat patient under the same condition, daily CT scans were also peformed before every treatment and the motion of lens was compared to the planning CT Setup errors for four volunteers were within 1mm and the motion of eyeball was fixed within the clinically acceptable ranges. For the patient with uveal melanoma, the motion of lens was fixed within 2mm from daily CT scans. An eye fixing and monitoring system allowed Immobilizing patient as well as monitoring eyeball and was successfully implemented in the treatment of uveal melanoma for SRS.

• Journal of Korean Home Economics Education Association
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• v.32 no.2
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• pp.59-76
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• 2020

The purpose of this study was to develop and evaluate the teaching/learning process plan of 'housing culture and practical space use' for home economics in middle school according to the problem based learning(PBL) model. The plan consisting of 4-lessons has been developed and implemented following the steps of ADDIE model. Various activity materials (4 scenarios, 6 individual activity sheets, 10 reading texts, and 5 working resources) and visual materials (4 sets of ppt and 4 moving pictures) as well as questionnaire were developed for the 4-session lessons. The plans were implemented to a single class of 21 junior students at H middle school in rural area, Kyeongnam, from 1^st to 12^th of April, 2019. Students highly enjoyed and were satisfied with the whole 4-lessons in aspects such as understanding of the contents, adequacy of materials and activities, and usefulness in one's own daily life. Additionally, they have more actively participated in the lessons than usual and even interested in learning more of such lessons. Students also reported that they highly accomplished the goal of each lesson as well as overall objectives. They showed interest in the major part of PBL lesson such as scenario and group activities. And they engaged themselves in drawing the share housing space plan with '5D planner' web program which they described as the best part of the lessons. The teaching/learning process plan developed in this study may be used as a theme of maker education, which is emerging these days. It can be concluded that the PBL teaching/learning process plans for 'housing values and practical space use' would contribute to improving students' attitude on living with others and ability to manage one's individual life.

• The korean journal of orthodontics
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• v.37 no.2 s.121
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• pp.98-113
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• 2007

Objective: The purpose of this study was to evaluate the displacement pattern and the stress distribution shown on a finite element model 3-D visualization of a dry human skull using CT during the retraction of upper anterior teeth. Methods: Experimental groups were differentiated into 8 groups according to corticotomy, anchorage (buccal: mini implant between the maxillary second premolar and first molar and second premolar reinforced with a mini Implant, palatal: mini implant between the maxillary first molar and second molar and mini implant on the midpalatal suture) and force application point (use of a power arm or not). Results: In cases where anterior teeth were retracted by a conventional T-loop arch wire, the anterior teeth tipped more postero-inferiorly and the posterior teeth moved slightly in a mesial direction. In cases where anterior teeth were retracted with corticotomy, the stress at the anterior bone segment was distributed widely and showed a smaller degree of tipping movement of the anterior teeth, but with a greater amount of displacement. In cases where anterior teeth were retracted from the buccal side with force applied to the mini implant placed between the maxillary second premolar and the first molar to the canine power arm, it showed that a smaller degree of tipping movement was generated than when force was applied to the second premolar reinforced with a mini implant from the canine bracket. In cases where anterior teeth were retracted from the palatal side with force applied to the mini implant on the midpalatal suture, it resulted in a greater degree of tipping movement than when force was applied to the mini implant between the maxillary first and second molars. Conclusion: The results of this study verifies the effects of corticotomies and the effects of controlling orthodontic force vectors during tooth movement.

• Journal of the Korean Geographical Society
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• v.40 no.2 s.107
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• pp.221-241
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• 2005

Land Use and Land Cover Changes (LUCC) occur over a wide range of space and time scales, and involve complex natural, socio-economic, and institutional processes. Therefore, modelling and predicting LUCC demands an understanding of how various measured properties behave when considered at different scales. Understanding spatial and temporal variability of driving forces and constraints on LUCC is central to understanding the scaling issues. This paper aims to 1) assess the heterogeneity of land cover change processes over the landscape in northern Ghana, where intensification of agricultural activities has been the dominant land cover change process during the past 15 years, 2) characterise dominant land cover change mechanisms for various spatial scales, and 3) identify the optimal spatial scale for LUCC modelling in a savanna landscape. A multivariate statistical method was first applied to identify land cover change intensity (LCCI), using four time-sequenced NDVI images derived from LANDSAT scenes. Three proxy land use change predictors: distance from roads, distance from surface water bodies, and a terrain characterisation index, were regressed against the LCCI using a multi-scale hierarchical adaptive model to identify scale dependency and spatial heterogeneity of LUCC processes. High spatial associations between the LCCI and land use change predictors were mostly limited to moving windows smaller than 10$\times$10km. With increasing window size, LUCC processes within the window tend to be too diverse to establish clear trends, because changes in one part of the window are compensated elsewhere. This results in a reduced correlation between LCCI and land use change predictors at a coarser spatial extent. The spatial coverage of 5-l0km is incidentally equivalent to a village or community area in the study region. In order to reduce spatial variability of land use change processes for regional or national level LUCC modelling, we suggest that the village level is the optimal spatial investigation unit in this savanna landscape.

• Journal of the Society of Disaster Information
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• v.10 no.4
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• pp.518-527
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• 2014

Our society is changed and diversified rapidly and such tendency is accelerated day after day and has made a lot of problems in the many fields. The important thing we have to recognize is such tendency has a bad effect recently on the safety system in Korea. So it is time to enhance the national safety system and moreover recently Sewol-ho(passenger ship) went down in the sea, it made people remind the importance of national safety system. With this incident, Korean government decided to establish the national safety communication network against the disaster. At this time, I will propose several ideas about the national safety communication network. 1. It must to be established an unified network to contact people who is on a disaster site anytime and anywhere. This is most important element on all disaster sites. 2. PS-LTE technology must to be adopted to the network because it has many advantages including various multimedia services compared to the TETRA in the past. 3. 700MHz is the most efficient band for the network because it has wide cell sites coverage compared to 1.8GHz. 4. Satellite communication system is needed to the network for back-up. 5. It will be effective to adopt Social Media to the communication network system like a Twitter or Facebook for sharing many kinds of information and notifying people of warning message. 6. It can make the network more useful to introduce the latest technology like a sensor network. And Korean government has to improve the system related to the disaster including law and operating organization.

• Journal of Korean Society of Transportation
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• v.22 no.7 s.78
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• pp.119-129
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• 2004

This paper is designed to report the results of development and validation procedures in relation to the Freeway Incident Management System (FIMS) prototype development as part of Intelligent Transportation Systems Research and Development program. The central core of the FIMS is an integration of the component parts and the modular, but the integrated system for freeway management. The whole approach has been component-orientated, with a secondary emphasis being placed on the traffic characteristics at the sites. The first action taken during the development process was the selection of the required data for each components within the existing infrastructure of Korean freeway system. After through review and analysis of vehicle detection data, the pilot site led to the utilization of different technologies in relation to the specific needs and character of the implementation. This meant that the existing system was tested in a different configuration at different sections of freeway, thereby increasing the validity and scope of the overall findings. The incident detection module has been performed according to predefined system validation specifications. The system validation specifications have identified two component data collection and analysis patterns which were outlined in the validation specifications; the on-line and off-line testing procedural frameworks. The off-line testing was achieved using asynchronous analysis, commonly in conjunction with simulation of device input data to take full advantage of the opportunity to test and calibrate the incident detection algorithms focused on APID, DES, DELOS and McMaster. The simulation was done with the use of synchronous analysis, thereby providing a means for testing the incident detection module.