• Journal of the Institute of Electronics Engineers of Korea SD
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• v.40 no.5
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• pp.345-353
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• 2003

When designing network processors or implementing network equipments such as routers are implemented, IP lookup operations cause the major impact on their performance. As the organization of the IP address becomes simpler, the speed of the IP lookup operations can go faster. However, since the efficient management of IP address is inevitable due to the increasing number of network users, the address organization should become more complex. Therefore, for both IPv4(IP version 4) and IPv6(IP version 6), it is the essential fact that IP lookup operations are difficult and tedious. Lots of researcher for improving the performance of IP lookups have been presented, but the good solution has not been came out. Software approach alleviates the memory usage, but at the same time it si slow in terms of searching speed when performing an IP lookup. Hardware approach, on the other hand, is fast, however, it has disadvantages of producing hardware overheads and high memory usage. In this paper, conventional researches on IP lookups are shown and their advantages and disadvantages are explained. In addition, by mixing two representative structures, a new hybrid parallel architecture for fast IP lookups is proposed. The performance evaluation result shows that the proposed architecture provides better performance and lesser memory usage.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.44 no.5
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• pp.1-10
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• 2007

Most of natural images have a special property, what is called self-similarity, which is the basis of fractal image coding. Even though an image has local stationarity in several homogeneous regions, it is generally non-stationarysignal, especially in edge region. This is the main reason that poor results are induced in linear techniques. In order to overcome the difficulty we propose a non-linear technique using self-similarity in the image. In our work, an image is classified into stationary and non-stationary region with respect to sample variance. In case of stationary region, do-noising is performed as simply averaging of its neighborhoods. However, if the region is non-stationary region, stationalization is conducted as make a set of center pixels by similarity matching with respect to bMSE(block Mean Square Error). And then do-nosing is performed by Gaussian weighted averaging of center pixels of similar blocks, because the set of center pixels of similar blocks can be regarded as nearly stationary. The true image value is estimated by weighted average of the elements of the set. The experimental results show that our method has better performance and smaller variance than other methods as estimator.

• Journal of Information Technology and Architecture
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• v.10 no.1
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• pp.79-91
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• 2013

This paper proposes a systematic methodology that could be used to decide which one shows the best performance among space filling curves (SFCs) in applying lower-dimensional transformations to histogram sequences. A histogram sequence represents a time-series converted from an image by the given SFC. Due to the high-dimensionality nature, histogram sequences are very difficult to be stored and searched in their original form. To solve this problem, we generally use lower-dimensional transformations, which produce lower bounds among high dimensional sequences, but the tightness of those lower-bounds is highly affected by the types of SFC. In this paper, we attack a challenging problem of evaluating which SFC shows the better performance when we apply the lower-dimensional transformation to histogram sequences. For this, we first present a concept of spatial locality, which comes from an intuition of "if the entries are adjacent in a histogram sequence, their corresponding cells should also be adjacent in its original image." We also propose spatial locality preservation metric (slpm in short) that quantitatively evaluates spatial locality and present its formal computation method. We then evaluate five SFCs from the perspective of slpm and verify that this evaluation result concurs with the performance evaluation of lower-dimensional transformations in real image matching. Finally, we perform k-NN (k-nearest neighbors) search based on lower-dimensional transformations and validate accuracy of the proposed slpm by providing that the Hilbert-order with the highest slpm also shows the best performance in k-NN search.

• The KIPS Transactions:PartD
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• v.15D no.6
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• pp.793-802
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• 2008

The development methods which utilize OSSs have been tried as new alternative to solve limits of the previous software developments such as the quality of software, and time and cost of developments. Especially, small and medium companies are suffering from difficulty in applying large-scale development methodology whenever they develop softwares. Therefore, in the current situation that demand for small-scale development methodology is increasing, the methods of utilizing OSSs can become an efficient way to save costs and reduce a development period. Accordingly, analysis of open-source is no fixed procedure or method to utilize open-source for software developments in the field. In this thesis, to solve such problems, we propose the procedures and methods for identifying and selecting suitable open-source, and effective methods for improvement and integration through least modification on the basis of synthesis of existing researches and experiences in development projects. For selection of OSSs, we did identify correct requirements for the software to be developed, investigate the open-source just matching with such requirements, draw a candidate index, establish assessment criteria, and the consequently present a method to select OSSs. And, we deduced the validity and improvement of each detailed activity from practical application to an actual project and assessment.

• Korean Journal of Optics and Photonics
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• v.26 no.1
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• pp.23-29
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• 2015

In this paper, we propose a microscope system for detecting both a tumor and blood vessels in brain tumor surgery as fluorescence images by using multiple light sources and a beam-splitter module. The proposed method displays fluorescent images of the tumor and blood vessels on the same display device and also provides accurate information about them to the operator. To acquire a fluorescence image, we utilized 5-ALA (5-aminolevulinic acid) for the tumor and ICG (Indocyanine green) for blood vessels, and we used a beam-splitter module combined with a microscope for simultaneous detection of both. The beam-splitter module showed the best performance at 600 nm for 5-ALA and above 800 nm for ICG. The beam-splitter is flexible to enable diverse objective setups and designed to mount a filter easily, so beam-splitter and filter can be changed as needed, and other fluorescent dyes besides 5-ALA and ICG are available. The fluorescent images of the tumor and the blood vessels can be displayed on the same monitor through the beam-splitter module with a CCD camera. For ICG, a CCD that can detect the near-infrared region is needed. This system provides the acquired fluorescent image to an operator in real time, matching it to the original image through a similarity transform.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.42 no.6
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• pp.133-140
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• 2005

This paper presents a rapid face shape acquisition system. The system is composed of two cameras and one projector. The technique works by projecting a pattern on the object and capturing two images with two cameras. We use a 'one shot' system which provides 3D data acquired by single image per camera. The system is good for rapid data acquisition as our purpose. We use the 'absolutely coded pattern' using the hue and saturation of pattern lines. In this 'absolutely coded pattern' all patterns have absolute identification numbers. We solve the correspondence problem between the two images by using epipolar geometry and absolute identification numbers. In comparison to the 'relatively coded pattern' which uses relative identification numbers, the 'absolutely coded pattern' helps obtain rapid 3D data by one to one point matching on an epipolar line. Because we use two cameras, we obtain two images which have similar hue and saturation. This enables us to have the same absolute identification numbers in both images, and we can use the absolutely coded pattern for solving the correspondence problem. The proposed technique is applied to face data and the total time for shape acquisition is estimated.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.45 no.1
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• pp.55-63
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• 2008

Ridge orientations of fingerprint image are crucial informations in many parts of fingerprint recognition such as enhancement, matching and classification. Therefore it is essential to extract the ridge orientations of image accurately because it directly affects the performance of the system. The two main properties of ridge orientation are 1) global characteristic(gradual change in whole part of fingerprint) and 2) local characteristic(abrupt change around core and delta points). When we only consider the local characteristic, estimated ridge orientations are well around singular points but not robust to noise. When the global characteristic is only considered, to estimate ridge orientation is robust to noise but cannot represent the orientation around singular points. In this paper, we propose a novel method for estimating ridge orientation which represents local characteristic specifically as well as be robust to noise. We reduce the noise caused by scar using iterative outlier rejection. We apply adaptive measurement resolution in each fingerprint area to estimate the ridge orientation around singular points accurately. We evaluate the performance of proposed method using synthetic fingerprint and FVC 2002 DB. We compare the accuracy of ridge orientation. The performance of fingerprint authentication system is evaluated using FVC 2002 DB.

• Journal of Cadastre & Land InformatiX
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• v.50 no.1
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• pp.215-229
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• 2020

In response to the recent 4th industrial revolution, the demand for 3D object models in the latest fields of digital twin, autonomous driving, and VR/AR, as well as the existing fields such as city, construction, transportation, and energy has increased significantly. It is expected that the demand for 3D object models with various precision from LOD1 to LOD4 will increase more and more in various industry fields. However, the Ministry of Land, Infrastructure and Transport, and the local government and the private sector have partially built 3D object models of different precisions for some specific regions because of the huge cost. Therefore, this study proposes a feasible plan that can solve the cost problem in generating 3D object models for the whole territory. For our purpose, we first analyzed usage, demand, generation technology and generation cost for 3D object models. Afterwards, we proposed LOD3 model generation plan for all territory using automatic 3D object model generation technology based on image matching. Additionally, we supplemented the proposed plan by using LOD4 generation plan for landmarks and LOD2 generation plan non-urban area. In the near future, we expect this would be a great help in establishing a feasible and effective 3D object model generation plan for the whole country.

• Korean Journal of Soil Science and Fertilizer
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• v.17 no.2
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• pp.96-100
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• 1984

To give basic information on the agricultural mechanization and multiple cropping adoptability of the paddified clayey terrace soils which have poor permeability and poor adoptability to mechanization, a scheme of drainage classification as well as taxonomic classification was intended. 1. The degrees of gleization of terrace paddy soils were well distinguished by the comparison of "Redness rating" of their profiles. 2. When the criteria of "Imperfectly drained" soils were defined as follows; Soils have more than 50cm of accumulated depth which has less than 0.5 in Redness rating within 1.2m of the profile, the Geugrag series could be classified to "Imperfectly drained." The tentative classification of drainage class of Geugrag soils seemed to well matching with land suitability groups, and give possibility of drainage recommendation in the case of dry land crop cultivation. 3. The Geugrag soil which was well paddified by artificial surface irrigation, could be proposed to classify "Anthroaquic Ochraqualfs."

• The Korean Journal of Health Service Management
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• v.3 no.1
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• pp.14-24
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• 2009

This study aims at deriving any useful information necessary to strengthen the competitiveness for growth through empirical analyses on general hospital located in a province in order to countermeasure the opening and competition of medical markets. The characteristics of user were identified on the basis of disease groups under KCD in the research method. In addition, the analysis on the expenses of diagnosis and treatment was divided into the treatment progress and degree of hospital resource utilization And the regression was carried out to identify the impacts of characteristics of inpatient users on the degree of hospital resource utilization. As a result of major research, the inpatient users of the general hospital located in the provincial area in consideration of inpatient users were formed around the inpatient disease groups representative for Korea(diseases of the respiratory system, injury and poisoning & certain other consequences of external causes). And it was understood that most of residents within a distance of 40 minute by the public transportation were using. And mostly were under the age of 9 or over 60, and the provision of medical features such as the degree of consultation and operational functions were inadequate. When we classify inpatient treatment cost for each resource application as the medical cost being the center of patient care function, the equipment and human resource application sector are constituted over half. Accordingly, the following suggestions are made as plans to strengthen the competitiveness for the growth of general hospitals located in the provincial areas on the basis of analytical results. First, it is necessary to have the characterization matching to the age and disease groups with a high frequency. Second, it is necessary to increase the degree of hospital resource utilization according to the characterization. Third, it is necessary to concentrate on public relations. The above suggestion, as a method for securing image improvement and competitive power as a general hospital, and through expansion of social function that a regional general hospital needs to secure not only as an individual institution but also as a general hospital, it can be seen that a general improvement of image as a regional general hospital is possible.