• The KIPS Transactions:PartB
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• v.9B no.3
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• pp.375-382
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• 2002

Handwritten character recognition is classified into on-line handwritten character recognition and off-line handwritten character recognition. On-line handwritten character recognition has made a remarkable outcome compared to off-line hacdwritten character recognition. This method can acquire the dynamic written information such as the writing order and the position of a stroke by means of pen-based electronic input device such as a tablet board. On the contrary, Any dynamic information can not be acquired in off-line handwritten character recognition since there are extreme overlapping between consonants and vowels, and heavily noisy images between strokes, which change the recognition performance with the result of the preprocessing. This paper proposes a method that effectively extracts the stroke including dynamic information of characters for off-line Korean handwritten character recognition. First of all, this method makes improvement and binarization of input handwritten character image as preprocessing procedure using watershed algorithm. The next procedure is extraction of skeleton by using the transformed Lu and Wang's thinning: algorithm, and segment pixel array is extracted by abstracting the feature point of the characters. Then, the vectorization is executed with a maximum permission error method. In the case that a few strokes are bound in a segment, a segment pixel array is divided with two or more segment vectors. In order to reconstruct the extracted segment vector with a complete stroke, the directional component of the vector is mortified by using right-hand writing coordinate system. With combination of segment vectors which are adjacent and can be combined, the reconstruction of complete stroke is made out which is suitable for character recognition. As experimentation, it is verified that the proposed method is suitable for handwritten Korean character recognition.

• Journal of Periodontal and Implant Science
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• v.31 no.1
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• pp.207-227
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• 2001

스프린트는 치주처지료에서 부가적 처치법으로 널리 사용되고 있으며, 한편, 디지털 공제 활영술은 기존방사선촬영술의 한계점을 극복하기 위해 기발된 새로운 방법이다. 이번 연구에서는 치근활택술 단독시행시와 스피린트 병행 처치시의 효과를 임상적, 방사선학적으로 비교하였다. 중정도의 성인성 치주염을 가진 20명의 환자를 대상으로 하되 10명은 치근활택술 단독으로, 나머지 10명은 스프린트 병행처치로 처치하였다. 임상적, 방사선학적인 평가는 처치전, 처치후 6개월에 행하고, 임상적 평가의 경우 3개월에 추가로 실시하였다. 이번 연구에서 사용된 임상 지수로는 치태지수, 치은지수, 치은퇴축, 치주낭깊이, 임상부착수준, 임상부착증가, 탐침시출혈, 치아동요도 등이며, 방사선학적 평가는 기존 방사선촬영술에 의한 방법과 디지털 공제촬영수렝 의한 방법으로 행하였다. 디지털 공제 촬영술에 의한 평가시, 영상은 Digora 프로그램에 의해 획득하고 Emago 프로그램으로 처리 하여 다음과 같은 결론을 얻었다. 1. 처치후 3개월에 치태지수, 치은지수, 치은퇴축, 치주낭깊이, 임상적부착수준, 탐침시 출혈 등의 임상지수들이 변했으며, 특히 이러한 변화는 치주낭깊이, 치은퇴축, 탐침시출혈에서 유의성이 있었다. ( p<0.05 ) 그러나 두군간 차이는 인정되지 않았다. ( p>0.05 ) 2. 처치후 6개월에도 치태지수, 치은지수, 치은퇴축, 치주낭깊이, 임상적부착수준, 탐침시출혈, 치아동요도 등의 임상지수들이 변했으며, 특히 이러한 변화는 치주낭깊이, 치은퇴축, 탐침시출혈, 치태지수, 치아동요도에서 유의성이 있었다. ( p<0.05 ) 그러나 두 군간 차이는 인정되지 않았다. ( p>0.05 ) 3. 켄달 상관분석시, 임상적 평가와 기존 방사선 촬영술에 의한 평가사이의 관련성을 낮았으며 거의 0에 가까운 수치를 보였으며 (r=0.110, p=0.639 ) 임상적 평가와 디지털 공제 방사선 촬영술에 의한 평가사이에서 약간 높은 관련성을 보였다. ( r=0.257, p=0.315 ) 즉 치주치료후의 골변화는 디지털 공제 방사선 촬영술에 의한 평가시 기존 방사선 사진보다 임상적 부착증가와 더욱 긴밀한 관련성을 보여준다. 이상의 결과로 볼 때, 스프린팅 처치는 치주 치료에 있어 치근활택술에 부가적 표과를 제공하지 못한다.

• Journal of Biosystems Engineering
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• v.28 no.6
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• pp.517-524
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• 2003

There have been worldwide research and development efforts to automate various processes of bio-production and those efforts will be expanded with priority given to tasks which require high intensive labor or produce high value-added product and tasks under hostile environment. In the field of bio-production capabilities of the versatility and robustness of automated system have been major bottlenecks along with economical efficiency. This paper introduces a new concept of automation based on tole-operation, which can provide solutions to overcome inherent difficulties in automating bio-production processes. Operator(farmer), computer, and automatic machinery share their roles utilizing their maximum merits to accomplish given tasks successfully. Among processes of greenhouse watermelon cultivation tasks such as pruning, watering, pesticide application, and harvest with loading were chosen based on the required labor intensiveness and functional similarities to realize the proposed concept. The developed system was composed of 5 major hardware modules such as wireless remote monitoring and task control module, wireless remote image acquisition and data transmission module, gantry system equipped with 4 d.o.f. Cartesian type robotic manipulator, exchangeable modular type end-effectors, and guided watermelon loading and storage module. The system was operated through the graphic user interface using touch screen monitor and wireless data communication among operator, computer, and machine. The proposed system showed practical and feasible way of automation in the field of volatile bio-production process.

• Journal of Dental Rehabilitation and Applied Science
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• v.29 no.3
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• pp.249-258
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• 2013

The purpose of this study was to investigate how image magnification in dental panoramic radiography is influenced by object position. Five metal balls (4 mm in diameter, 2 for the anterior and 3 for the posterior region on the right side) were placed above alveolar crest of dry skull considering extraction socket and dental arch. Dry skull was radiographed using OP-100D (Instrumentarium Imaging Co., Tuusula, Finland) at proper and displaced position along the sagittal and transverse plane at 3 mm, 6 mm, 9 mm, 12 mm and 15 mm using special mount which can control precise movement. Images were stored in DICOM files and were measured by ruler equipped within INFINITT PACS software (Infinitt Co., Ltd., Seoul, Korea). The mean horizontal magnification was 1.224-1.439 and mean vertical magnification was 1.286 - 1.345 at proper position. Vertical magnification resulted in less variation (1.245-1.418) than horizontal magnification (0.798-6.297) according to the sagittal and transverse displacements. Head positioning is important for linear measurement on panoramic radiography and inclusion of standard object (for instance, metal ball) is helpful to anticipate exact magnification of panoramic radiographs at various location.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.6
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• pp.1036-1043
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• 2022

This paper discusses about the development of a visual sensor that can be installed in an automatic mooring device to detect the berthing condition of a vessel. Despite controlling the ship's speed and confirming its location to prevent accidents while berthing a vessel, ship collision occurs at the pier every year, causing great economic and environmental damage. Therefore, it is important to develop a visual system that can quickly obtain the information on the speed and location of the vessel to ensure safety of the berthing vessel. In this study, a visual sensor was developed to observe a ship through an image while berthing, and to properly check the ship's status according to the surrounding environment. To obtain the adequacy of the visual sensor to be developed, the sensor characteristics were analyzed in terms of information provided from the existing sensors, that is, detection range, real-timeness, accuracy, and precision. Based on these analysis data, we developed a 3D visual module that can acquire information on objects in real time by conducting conceptual designs of LiDAR (Light Detection And Ranging) type 3D visual system, driving mechanism, and position and force controller for motion tilting system. Finally, performance evaluation of the control system and scan speed test were executed, and the effectiveness of the developed system was confirmed through experiments.

• Nuclear Medicine and Molecular Imaging
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• v.42 no.5
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• pp.383-393
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• 2008

Purpose: Cancer specific killing can be achieved by therapeutic gene activated by cancer specific promotor. Expression of sodium iodide symporter (NIS) gene causes transportation and concentration of iodide into the cell, therefore radioiodine treatment after NIS gene transfer to cancer cell could be a form of radionuclide gene therapy. luciferase (Luc) gene transfected cancer cell can be monitored by in vivo optical imaging after D-luciferin injection. Aims of the study are to make vector with both therapeutic NIS gene driven by AFP promoter and reporter Luc gene driven by CMV promoter, to perform hepatocellular carcinoma specific radiodiodine gene therapy by the vector, and assessment of the therapy effect by optical imaging using luciferase expression. Materials and Methods: A Vector with AFP promoter driven NIS gene and CMV promoter driven Luc gene (AFP-NIS-CMV-Luc) was constructed. Liver cancer cell (HepG2, Huh-7) and non liver cancer cell (HCT-15) were transfected with the vector using liposome. Expression of the NIS gene at mRNA level was elucidated by RT-PCR. Radioiodide uptake, perchlorate blockade, and washout tests were performed and bioluminescence also measured by luminometer in these cells. In vitro clonogenic assay with 1-131 was performed. In vivo nuclear imaging was obtained with gamma camera after 1-131 intraperitoneal injection. Results: A Vector with AFP-NIS-CMV-Luc was constructed and successfully transfected into HepG2, Huh-7 and HCT-15 cells. HepG2 and Huh-7 cells with AFP-NIS-CMV-Luc gene showed higher iodide uptake than non transfected cells and the higher iodide uptake was totally blocked by addition of perchlorate. HCT-15 cell did not showed any change of iodide uptake by the gene transfection. Transfected cells had higher light output than control cells. In vitro clonogenic assay, transfected HepG2 and Huh-7 cells showed lower colony count than non transfected HepG2 and Huh-7 cells, but transfected HCT-15 cell did not showed any difference than non transfected HCT-15 cell. Number of Huh-7 cells with AFP-NIS-CMV-Luc gene transfection was positively correlated with radioidine accumulation and luciferase activity. In vivo nuclear imaging with 1-131 was successful in AFP-NIS-CMV-Luc gene transfected Huh-7 cell xenograft on nude mouse. Conclusion: A Vector with AFP promoter driven NIS and CMV promoter driven Luc gene was constructed. Transfection of the vector showed liver cancer cell specific enhancement of 1-131 cytotoxicity by AFP promoter, and the effect of the radioiodine therapy can be successfully assessed by non-invasive luminescence measurement.

• Journal of the Korean Society of Radiology
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• v.11 no.1
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• pp.27-35
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• 2017

The purpose of this study was to investigate the features of CsI:Tl and $Gd_2O_2S$ detectors with an indirect conversion method using phantom in the DR (digital radiography) system by obtaining images of thick chest phantom, medium thickness thigh phantom, and thin hand phantom and by analyzing the SNR and CNR. As a result of measuring the SNR and CNR according to the thickness change of the subject, the SNR and CNR were higher in CsI:Tl detector than in $Gd_2O_2S$ detector when the medium thickness thigh phantom and thin hand phantom were scanned. However, when the thick chest phantom was used, for the SNR at 80~125 kVp and the CNR at 80~110 kVp in the $Gd_2O_2S$ detector, the values were higher than those of CsI:Tl detector. The SNR and CNR both increased as the tube voltage increased. The SNR and CNR of CsI:Tl detector in the medium thickness thigh phantom increased at 40~50 kVp and decreased as the tube voltage increased. The SNR and CNR of $Gd_2O_2S$ detector increased at 40~60 kVp and decreased as the tube voltage increased. The SNR and CNR of CsI:Tl detctor in the thin hand phantom decreased at the low tube voltage and increased as the tube voltage increased, but they decreased again at 100~110 kVp, while the SNR and CNR of $Gd_2O_2S$ detector were found to decrease as the tube voltage increased. The MTF of CsI:Tl detector was 6.02~90.90% higher than that of $Gd_2O_2S$ detector at 0.5~3 lp/mm. The DQE of CsI:Tl detector was 66.67~233.33% higher than that of $Gd_2O_2S$ detector. In conclusion, although the values of CsI:Tl detector were higher than those of $Gd_2O_2S$ detector in the comparison of MTF and DQE, the cheaper $Gd_2O_2S$ detector had higher SNR and CNR than the expensive CsI:Tl detector at a certain tube voltage range in the thick check phantom. At chest X-ray, if the $Gd_2O_2S$ detector is used rather than the CsI:Tl detector, chest images with excellent quality can be obtained, which will be useful for examination. Moreover, price/performance should be considered when determining the detector type from the viewpoint of the user.

• The Journal of Korean Society for Radiation Therapy
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• v.26 no.1
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• pp.69-76
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• 2014

Purpose : To evaluate the changes of the motion of abdominal cavity between interfraction and intrafraction by using abdominal compression for reducing abdominal motion. Materials and Methods : 60 MVCT images were obtained before and after tomotherapy from 10 prostate cancer patients over the whole radiotherapy period. Shift values ( X -lateral Y -longitudinal Z -vertical and Roll ) were measured and from it, the correlation of between interfraction set up change and intrafraction target motion was analyzed when applying abdominal compression. Results : The motion changes of interfraction were X-average $0.65{\pm}2.32mm$, Y-average $1.41{\pm}4.83mm$, Z-average $0.73{\pm}0.52mm$ and Roll-average $0.96{\pm}0.21mm$. The motion changes of intrafraction were X-average $0.15{\pm}0.44mm$, Y-average $0.13{\pm}0.44mm$, Z-average $0.24{\pm}0.64mm$ and Roll-average $0.1{\pm}0.9mm$. The average PTV maximum dose difference was minimum for 10% phase and maximum for 70% phase. The average Spain cord maximum dose difference was minimum for 0% phase and maximum for 50% phase. The average difference of $V_{20}$, $V_{10}$, $V_5$ of Lung show bo certain trend. Conclusion : Abdominal compression can minimize the motion of internal organs and patients. So it is considered to be able to get more ideal dose volume without damage of normal structures from generating margin in small in producing PTV.

• Economic and Environmental Geology
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• v.44 no.6
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• pp.463-474
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• 2011

The Haenam epithermal mineralized zone is located in the southwestern part of South Korea, and hosts low sulfidation epithermal Au-Ag deposit (Eunsan-Moisan) and clay quarries (Okmaesan, Seongsan, and Chunsan). Epithermal deposits and accompanying hydrothermal alteration related to Cretaceous volcanism caused large zoned assemblages of hydrothermal alteration minerals. Advanced argillic-altered rocks with mineral assemblages of alunite-quartz, alunite-dickite-quartz, and dickite-kaolinite-quartz exposed on the Okmaesan, Seongsan, and Chunsan area. Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), with three visible and near infrared bands, six shortwave infrared bands, and five thermal infrared bands, was used to identify advanced argillic-altered rocks within the Haenam epithermal mineralized zone. The distinct spectral features of hydrothermal minerals allow discrimination of advanced argillic-altered rocks from non-altered rocks within the study area. Because alunite, dickite, and kaolinite, consisting of advanced argillic-altered rocks within the study area are characterized by Al-O-H-bearing minerals, these acid hydrothermal minerals have a strong absorption feature at $2.20{\mu}m$. The band combination and band ratio transformation cause increasing differences of DN values between advanced argillic-altered rock and non-altered rock. The alunite and dickite-kaolinite of advanced argillic-altered rocks from the Okmaesan, Seongsan, and Chunsan have average DN values of 1.523 and 1.737, respectively. These values are much higher than those (1.211 and 1.308, respectively) of non-altered area. ASTER images can remotely provide the distribution of hydrothermal minerals on the surface. In this way good relation between ASTER spectra analysis and field data suggests that ASTER spectral analysis can be useful tool in the initial steps of mineral exploration.

• Geophysics and Geophysical Exploration
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• v.8 no.1
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• pp.67-72
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• 2005

To investigate the feasibility of a new concept of storing Liquefied Natural Gas (LNG) in a lined hard rock cavern, and to develop essential technologies for constructing underground LNG storage facilities, a small pilot plant storing liquid nitrogen (LN2) has been constructed at the Korea Institute of Geoscience and Mineral Resources (KIGAM). The LN2 stored in the cavern will subject the host rock around the cavern to very low temperatures, which is expected to cause the development of an ice ring and the change of ground condition around the storage cavern. To investigate and monitor changes in ground conditions at this pilot plant site, geophysical, hydrogeological, and rock mechanical investigations were carried out. In particular, geophysical methods including borehole radar and three-dimensional (3D) resistivity surveys were used to identify and monitor the development of an ice ring, and other possible changes in ground conditions resulting from the very low temperature of LN2 in the storage tank. We acquired 3D resistivity data before and after storing the LN2, and the results were compared. From the 3D images obtained during the three phases of the resistivity monitoring survey, we delineated zones of distinct resistivity changes that are closely related to the storage of LN2. In these results, we observed a decrease in resistivity at the eastern part of the storage cavern. Comparing the hydrogeological data and Joint patterns around the storage cavern, we interpret this change in resistivity to result from changes in the groundwater flow pattern. Freezing of the host rock by the very low temperature of LN2 causes a drastic change in the hydrogeological conditions and groundwater flow patterns in this pilot plant.