• Proceedings of the KIEE Conference
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• 2005.10b
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• pp.240-242
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• 2005

It is well known that the PD (Partial Discharge) signals are generated if insulators have some defects such as voids in electrical facility and various PD detection methods are developed for preventing electrical troubles. So, an interest for the PD signals is higher and higher according to the high concern for the defects detection method of the aging electrical facility. When the equipment to detect PD signals installed at site and it works, a lot of noises flow in the equipment from surrounding situation and it will be mixed with original PD waveform. So we can not get the desired PD waveform. Therefore, there are many trial to reject or suppress the noise from the PD signals from long times ago. The greater of them used the hardware such as bridge circuits and frequency filters to suppress the noise. This paper proposed a novel noise rejection method in acquired data from PD detection equipment. The noise has the irregular phase and higher signal level than real PD, and noise decision is performed after inspection of pulse distribution in ${\Phi}$-q-n graph of acquired data from PD detection equipments. By experimental results on high voltage electric equipments, it is shown that proposed method has good performance. It is expected that this noise rejection technology is useful in numeric calculation and trend management of PD level.

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.8
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• pp.704-709
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• 2016

Wave energy generation systems can be divided into oscillating water chamber type, over topping device type and wave activating body type. The wave activating body type converts wave energy to kinetic energy, and the power generation amount increases as the motion of an activating body increases. In this paper, the wave energy convertor consists of a main body, which has an H-shape, and the activating body. These are connected by a bar-type bridge. By the incident wave, when the activating body moves with vertical motion this motion is consequently converted into rotational motion. The twisting moment and angular velocity at a shaft of convertor are calculated according to various conditions of the incident wave and the shape of the activating body. This can be used as a basic idea for determining the design of wave activating body type convertor.

• Journal of the Korean Institute of Rural Architecture
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• v.12 no.2
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• pp.135-142
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• 2010

This research aims to examine the characteristics of tomb sites including tomb mound and attached buildings and also to find out the principles reflected in the traditional oriental Feng-Shui location and spatial composition of Junkyung and Youngkyung tomb at Samcheok. The results of this study are as follows. These tombs harmonize with each other in the cosmic dual forces because Junkyung tomb is men's sex symbol and tiger to lie on his belly and Youngkyung tomb is women's sex symbol in geographical feature. Spatial structure in these tomb sites were placed in a reflected line following the hierarchy of metaphysics by standing high Geumchunkyo(Bridge)-Hongsalmun(Gate)-Jegak(Pavilion)-Bongbun(Tomb mound). Axis structure of these tombs is irregular bent-axis type from Geumchunkyo to Bongbun, specially in case of Youngkyung tomb it is getting more refractive. These tombs are divided into and characterized by three zones. Firstly the space for living people constitutes from Geumchunkyo to Hongsalmun, secondly the semi-sacred space constitutes from Hongsalmun to Jegak, and lastly the space for the dead constitutes from the back of Jegak to Bongbun. - type Jegak instead of T type Jegak generally used at Chosun Dynasty was installed because of claypan stretched out in front of Junkyung tomb and Bongbun of Youngkyung tomb located at a ravine between two mountain ranges.

• Journal of KIBIM
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• v.1 no.1
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• pp.26-31
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• 2011

Due to the characteristics of 3D objects of building construction projects which have regular, vertical and repetitive shapes, the most practical utilization of BIM in the country is focused on building projects. The characteristics of 3D objects of civil engineering project have irregular, horizontal and non-repetitive shapes. Therefore, consisting of a practical BIM model is difficult comparing with building project. This study suggests an application process of BIM for the planning and design phases for civil engineering project. A BIM system is developed based on suggested BIM process and it is verified through a bridge construction project.

• Smart Structures and Systems
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• v.16 no.1
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• pp.47-65
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• 2015

A novel finite element (FE) model updating method based on multi-resolution analysis (MRA) is proposed. The true stiffness of the FE model is considered as the superposition of two pieces of stiffness information of different resolutions: the pre-defined stiffness information and updating stiffness information. While the resolution of former is solely decided by the meshing density of the FE model, the resolution of latter is decided by the limited information obtained from the experiment. The latter resolution is considerably lower than the former. Second generation wavelet is adopted to describe the updating stiffness information in the framework of MRA. This updating stiffness in MRA is realized at low level of resolution, therefore, needs less number of updating parameters. The efficiency of the optimization process is thus enhanced. The proposed method is suitable for the identification of multiple irregular cracks and performs well in capturing the global features of the structural damage. After the global features are identified, a refinement process proposed in the paper can be carried out to improve the performance of the MRA of the updating information. The effectiveness of the method is verified by numerical simulations of a box girder and the experiment of a three-span continues pre-stressed concrete bridge. It is shown that the proposed method corresponds well to the global features of the structural damage and is stable against the perturbation of modal parameters and small variations of the damage.

• Journal of Veterinary Clinics
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• v.36 no.4
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• pp.233-237
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• 2019

A 10-year-old castrated male Shih Tzu dog was submitted to a local animal hospital with a mass from gingiva to maxillofacial skeleton. Computed tomography revealed that strong invasion of the mass result in osteolysis in orbit and frontal bone. The excised mass was presented to the Pathology Department of the Veterinary Medicine, Jeju National University. Surgically excised mass was rubbery to firm in consistency. Histologically, the neoplastic mass was composed of irregular or interdigitating cords, islands or pseudo-glandular structures of stratified epithelial cells. These cords or islands showed typical palisading pattern of neoplastic epithelial cells to periphery without intercellular bridge (desmosome) and surrounded by eosinophilic immature collagenous matrix. Some area showed islands of well differentiated keratinizing squamous cell foci. Some lumen of glandular structures contained fibrin-like materials and RBC. These neoplastic cells showed marked invasive tendency to adjacent connective tissues and bony tissues, therefore solitary neoplastic cells were widely distributed throughout the surround connective tissue. The neoplastic cells showed positive reactions for pan-CK and CK14, weakly positive reaction for CK5/6. And the surrounding immature collagenous matrix was only labeled for vimentin.

• Journal of The Geomorphological Association of Korea
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• v.27 no.3
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• pp.25-39
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• 2020

This study analyzed the management plan of Seomjin River Chimsil Wetland by identifying landscape changes through aerial photographs analysis and concentrations of sedimentation. Geophysical Landscape Change Analysis showed that vegetation accounts for more than half of the total area. The Barren land and water body was somewhere repeatedly increased and decreased and made an irregular form in the study area. The soil was acidic, and no eurtophication was shown, but it was potential to form wetland. In addition, the research area has been terrestrification of sand bar for a long period of time, forming a soil layer. Although the characteristics of river deposits were shown in the study area, the grain size was a particulate matter, and the sorting was 'very poorly sorted'. In some areas of Seomjin River Chimsil Wetland, sand bars were formed, but most areas were undergoing to terrestrification. Therefore, in order to preserve the riverine area and to serve by a bridge between the land ecosystem and the underwater ecosystem, it is very necessary to remove some vegetation, create a proper waterway, and restore the wetland.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.29 no.1
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• pp.21-29
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• 1993

The magnetic compass as a principal navigational instrument has been long used to fix ship's position and to determine ship's course. Particularly, in the small fishing vessels the studies on performance and rational usages for magnetic compass are requried to improve the safety and productivity of the small fishing vessels even though gyro compass is developed nowadays. For this purpose, the author examined the present condition of the magnetic compasses which are intalled on 219 small fishing vessels, and carried out a series of performance survey for each compass of them and also found the measured values of deviation by installation position of compass, respectively. The results obtained are summarized as follows: 1. The small fishing vessels less than 4 tons among the 219 small fishing vessels from 1 to 10 tons investigated were 50% of them. Only 1% of them were equipped with the deviation correctors, and 14 fishing vessels used the magnetic compasses which are more than 20 years old. 2. According to the compass installation position, the measured values of the deviation of the compass installed on the top bridge and the compass bed in bridge were ascertained to be the smallest, and those values of the compass installed on the bridge deck above engine room were larger and irregular. 3. The concomitant angle of the magnetic compasses installed on the experimented 4 fishing vessels were measured to be 6$^{\circ}$ to 16$^{\circ}$ and not accorded with the Korean standard values.

• Journal of the korean academy of Pediatric Dentistry
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• v.27 no.2
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• pp.333-343
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• 2000

The purpose of this study was to compare the effect of ferric sulfate and formocresol as pulp dressing agents in pulpotomized teeth of dogs. 40 teeth of 5 dogs, weighting 10kg. were used in this study. The animals were sacrificed at the intervals of 3, 7, 14, 28 and 56 days for histopathologic evaluation. The specimens were observed by the light microscope. The results were as follows : 1. Inflammatory response was observed in both groups, but pulp tissue of ferric sulfate group was showed lesser inflammatory degree and more rapid recovery than that of formocresol group. 2. In ferric sulfate group odontoblasts showed irregular arrangement pattern at initial stage and returned to regular pattern after 2 weeks. But in formocresol group. continued irregular pattern of odontoblast was observed during experimental period. 3. Reparative dentin was produced widely along the canal in one specimen of formocresol group at 8 weeks and dentinal bridge was formed in two specimens of ferric sulfate group at 8 weeks.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.36 no.6
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• pp.629-639
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• 2018

In this study, the application of the single beam echosounder and multi beam echosounder was analyzed for the Youngsan river, from the Juksanbo to the Juksan bridge, length of 840m, width 230m and area $0.16km^2$. A single beam echosounder and a multi beam echosounder are mounted on an USV (Unmanned Surface Vessel), and each data is acquired. Then, TIN (Triangular Irregular Network) is created and the grid depth of 10m intervals is extracted. The grid depth of the single beam echo sounder and the grid depth of the multi beam echo sounder were overlapped to compare the two data. As a result of analysis using 5,024 data, the mean depth difference was 0.0319m and the standard deviation was 2.4095m. The river bed shape was similar to each other. If the multi-beam echo sounder is regarded as the standard, the volume difference of the stream is $161,882m^3$. With a multi-beam echo sounder installed, the operating distance increased by approximately 55% to 4595.85m, and the operating time increased by approximately 59% to approximately 47%.