• Applied Microscopy
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• v.42 no.4
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• pp.194-199
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• 2012

The anatomy and morphology of seeds from 10 Hawaiian Portulaca taxa were examined to explore patterns of variation among the taxa, and to evaluate their phylogenetic relationships. Features of seeds were assessed employing microtechnique procedures, statistical analysis, and scanning electron microscopy (SEM). Anatomically, the orientation of embryo was consistent across taxa, and all seeds examined had central nutritive tissue and integuments comprising the peripheral embryo. Seeds were generally small, circular to ovoid in shape, and either smooth or rough-surfaced, with tubercules. Variation in seed size was noted, although minimal within small seeded group. The size of seeds ranged from 0.50~1.26 mm in length, and 0.55~1.34 mm in width, with similar weights. Seeds were distinguished by the sculpture and arrangement of the testa epidermis and the way in which their stellulate-tessellate cells uniquely fit together. Using a multiple range test (ANOVA), two groups were established by seed characteristics. The SEM also demonstrated morphological differences in testa sculpturing. The results obtained confirm the usefulness of seed characteristics in the identification of the species examined, and furthermore, allow for the separation of the Hawaiian Portulaca into two groups.

• Proceedings of the Korea Information Processing Society Conference
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• 2010.04a
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• pp.405-408
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• 2010

This paper presents a new feature extraction technique, correlation coefficient and Manhattan distance (MD) based method for recognition of rotated object in an image. This paper also represented a new concept of intensity invariant. We extracted global features of an image and converts a large size image into a one-dimensional vector called circular feature vector's (CFVs). An especial advantage of the proposed technique is that the extracted features are same even if original image is rotated with rotation angles 1 to 360 or rotated. The proposed technique is based on fuzzy sets and finally we have recognized the object by using histogram matching, correlation coefficient and manhattan distance of the objects. The proposed approach is very easy in implementation and it has implemented in Matlab7 on Windows XP. The experimental results have demonstrated that the proposed approach performs successfully on a variety of small as well as large scale rotated images.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.29 no.1
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• pp.241-254
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• 1999

The purpose of this study was to investigate whether a radiometric analysis of radicular cysts and periapical granulomas is useful in the differential diagnosis. In this experiment, twenty-nine periapical radiographs of the radicular cyst and those periapical granuloma were used. The periapical radiography was taken by intraoral paralleling device. The X-ray film was digitized and digitally filtered to reduce film-grain noise. We estimated density difference of the inner/outer area, roundness or circularity, bone profile or scan line of the margin and cumulative percentage frequency curve of radicular cyst & periapical granuloma. The obtained results were as follows; 1. The differences in density between ROIs of inner and outer area of radicular cysts were smaller than those of periapical granulomas. 2. The equivalent circular diameter was over 6.3mm, there was significant difference between periapical cyst and periapical granuloma. 3. In differential diagnosis of radicular cyst and periapical granuloma using bone profile. sensitivity. specificity and accuracy were considerably high(0.83. 0.86. 0.86) respectively. 4. Cumulative percentage frequency curve of the radicular cyst was closer to the pseudo-pixel value of 50 than average curve, whereas periapical granuloma was closer to that of 0. Hence we conclude that digital radiometric features might be useful in the differential diagnosis between radicular cyst and periapical granuloma.

• Advances in pediatric surgery
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• v.4 no.2
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• pp.93-99
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• 1998

Anal endosonography has recently been popularized in adult patients in order to access staging of rectal cancer and other lesions of the anorectum. This study is not familiar to pediatric surgeons. We performed anal endosonography in 30 children without anorectal disease in order to determine the standard morphology of the anorectum. The internal anal sphincter(IAS) was clearly identified as a homogeneous hypoechoic circular band, extending caudally to a level just proximal to the anal verge. The external anal sphincter(EAS) showed mixed echogenicity and different architecture along the anal canal; the EAS was U-shape in the upper canal and it had a circular pattern in the lower canal. In the upper canal of girls, the perineal body and the vagina were found just anterior of the anal canal, which made the U shape of the EAS. In the male, the sphincter tapered anteriorly into two arcs that met in the midline. The perineal body was prominent in the female. Posteriorly, the anococcygeal ligament was represented by a triangular shadow in both sex. The thickness of the IAS was measured in 3 directions, left, right and posterior, at 3 levels, upper, middle and lower areas of the anal canal. The average thickness was 0.86-2.40 mm between 6 and 18 months of age(Group 1), 0.88-3.20 mm between 19 and 36(Group 2), 1.07-2.20 mm between 37 and 54(Group 3) and 1.18-2.42 mm more than 54-month-old(Group 4). The thickness was correlated with the age of the children only in the right upper(p=0.008) and the left middle portion(p=0.015). We were able to obtain standard morphologic features of the normal anal canal in children with anal endosonography. We believe that this technique is a safe and an effective procedure to evaluate anorectal lesions in children.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.39 no.1
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• pp.70-76
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• 2002

In this paper, we proposed a personal identification algorithm using the iris region which has discriminant features. First, we acquired the eye image with the black and white CCD camera and extracted the iris region by using a circular edge detector which minimizes the search space for real center and radius of the iris. And then, we localized the iris region into several circles and extracted the features by filtering signals on the perimeters of circles with one dimensional Gabor filter We identified a person by comparing ,correlation values of input signals with the registered signals. We also decided threshold value minimizing average error rate for FRR(Type I)error rate and FAR(Type II)error rate. Experimental results show that proposed algorithm has average error rate less than 5.2%.

• Journal of the Korea Society of Computer and Information
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• v.15 no.7
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• pp.19-26
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• 2010

In this paper, we suggest a efficient handwritten character verification method in on-line environments which automatically analyses two input character string and computes their similarity degrees. The proposed algorithm first applies the circular projection method to input handwritten strings and extracts their representative features including shape, directions, etc. It then calculates the similarity between two character strings by using an improved dynamic time warping (DTW) algorithm. We improved the conventional DTW algorithm efficiently through adopting the branch-and-bound policy to the existing DTW algorithm which is well-known to produce good results in the various optimization problems. The experimental results to verify the performance of the proposed system show that the suggested handwritten character verification method operates more efficiently than the existing DTW and DDTW algorithms in terms of the speed.

• Journal of the Korean Society for information Management
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• v.26 no.3
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• pp.213-237
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• 2009

Local culture is a cultural heritage that has come down from generation to generation in the natural environment of a region. It includes history, tradition, natural features, art, and historic relics. The Academy of Korean Studies has complied "The Encyclopedia of Korean Local Culture" using those local culture contents. Local culture content shave the features of documentary, such as authenticating the source, and managing hierarchy structure. Thus, to deal with local culture contents, a "circular knowledge information management system" is sought for that helps basic, fragmentary, and high-level information to circulate to create new knowledge information within the system. A user of this circular knowledge information management system is able not only to collect data directly in it, but also to fetch data from other database. Besides, processing the collected data helps to create new knowledge information. But, it's very difficult to sustain the features of the original hierarchy bearing meaning contained in the various kinds of local culture contents when building a new database. Moreover, this kind of work needs many times of correction over a long period of time. Therefore, a system in which compilation, correction, and service can be done simultaneously is needed. Therefore, in this study, focusing on the case of "The Encyclopedia of Korean Local Culture", I propose a XML-based digital compilation management system that can express hierarchy information and sustain the semantic features of the local culture contents containing lots of ancient documents, and introduce the expanded functions developed to manage contents in the system.

• Journal of the Society of Naval Architects of Korea
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• v.49 no.4
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• pp.304-311
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• 2012

One of the main features of Drillship or FPSO is a moonpool structure. The moonpool structures have various accuracy tolerances according to their functions and targets. This study is mainly interested in roundness of a circular moonpool structure in FPSO. Because this structure needs abrasion-resistance at which bearing of machine touches on inner wall of moonpool, we should do over-lay welding widely and deeply by using Inconel weld material. But a general over-lay can cause a severe distortion at ship block structure. If we can analyze the roundness by thermal distortion under Inconel over-lay, we can establish a special erection policy by the results. In this study, we designed stress-strain curve for strain-boundary condition analysis by an elasto-plastic material property. The results made us to decide an appropriate ship-block size and policy of crane manipulation will follow for its capacity. If a structure that needs over-lay is not large, solid elements also are not a bad choice for FEM modeling. Therefore we also developed a standard of using strain-boundary method that shell elements are used as over-lay on solid element modeling.

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.5
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• pp.403-411
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• 2016

Usually shell and tube heat exchangers are employed to recover energy between fluids. Recently, numerous papers on these heat exchangers have been published; however, the velocity and temperature profiles or comparison of the features of the flow with or without inside tubes have rarely been described. In this research, experimental and numerical studies were carried out to investigate the characteristics of the flow around the spiral baffle plates without inside tubes in a horizontal circular tube using a particle image velocimetry method and ANSYS 14.0~15.0 version (Fluent). The results showed that swirling flow was produced between the spiral baffle plates. The tangential components were strong between the two spiral baffles; however, the axial or radial velocities components were indicating nearly zero. From the spiral motion in the space of the two baffles, it is considered that there were no dead zones between the spiral baffle.

• Journal of Navigation and Port Research
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• v.26 no.2
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• pp.199-207
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• 2002

Radar Cross Sections(RCS) for the radar targets are measured and their performance characteristics are analyzed through computer simulation. In addition, constructional features for the commercial radar reflectors are investigated. Then, the optimum design condition of a passive-type radar reflector was chosen. The results show that the octahedral-type radar reflector with 10$\lambda$ sized circular plates has best performance in X-band($\lambda$=3.2cm). However, to comply with newly adopted 2000 SOLAS regulations, larger sized circular plate is required to provide at both X-band and S-band.