• Korean Journal of Environment and Ecology
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• v.23 no.6
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• pp.545-552
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• 2009

This study was conducted to provide basic information for development of habitat-based conservation strategies of biological diversity in agricultural ecosystem. The carabid beetle assemblages were examined at four kinds of habitats(levee, dike, forest patch remnants and streamside) from three differently stressed areas located in Paltan-myun, Hwaseong city, Korea: agricultural and forest area(site 1), industrial area(site 2), and residential area(site 3). Pitfall trap samplings were carried out 39 times from November 2000 to November 2002. Our study's findings were that the composition of carabid beetle fauna, dominance species, and pattern of carabid beetle assemblage were different among the habitats. The similarity index was highest between two levees in site 2 and 3, and lowest between hillock in site 2 and streamside in site 3, and that among habitats fragmented by road with high traffic was lower than that among any other habitat types. So, we could know that agricultural land use respectively do an important role in diversity conservation and networking. These findings will be used to establish the land use and management plans in the aspects of conservation of biodiversity.

• Ocean and Polar Research
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• v.28 no.2
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• pp.129-144
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• 2006

Small-scale effects of sand mining on macrobenthic communities have been reported previously. However, little information is available as to how dredging affects the macrobenthic community structure. The objective of this study was to determine the impacts of large-scale exhibition dredging on the macrobenthic community of Gyeonggi Bay, Korea, where sand mining has continued for 20 years. Prior to dredging, the macrobenthic species composition was similar to that of areas near the dredging site, with several common dominant species found before dredging. After dredging, the number of species, density, and diversity (H') in the experimental area (sites 0 and 1) decreased significantly, but no difference was observed at other sites. Multivariate analysis (multidimensional scaling) revealed significant differences in community structure before and after dredging. The amphipod Urothoe grimaldii japonica, which was the most dominant species at sites 0,1, and 2, decreased rapidly at sites 0 and 1 after dredging, but no difference was observed at site 2. In addition, the index of multivariate dispersion (IMD) and the relative IMD (r. IMD) were large at sites 0 and 1, suggesting that the effects of dredging were direct at site 0 and 1, but indirect at site 2. The macrobenthic communities at sites 3 and 4 were not affected by dredging, but they were affected by physical conditions and biological interactions. We suggest that benthic biotope indices such as the IMD and r.IMD may constitute a valid tool for assessing the effects of dredging on the macrobenthic community; long-term monitoring is required to verify this.

• Journal of Korean Neurosurgical Society
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• v.30 no.4
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• pp.443-450
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• 2001

Objective : The cyclin-dependent kinase inhibitor $p27^{kip1}$ protein is a negative regulator of the cell cycle, and its degradation is required for entry into the S phase. Loss of $p27^{kip1}$ expression has been reported to be associated with aggressive behavior in a variety of tumors of epithelial and lymphoid origin. However, its association with various astrocytic tumors has not been clearly demonstrated. We studied to investigate the relationship of $p27^{kip1}$ expression with the biological behavior of astrocytic tumors in addition to study on the role of $p27^{kip1}$ in the tumorigenesis of these tumors. Patients and Methods : From 1990 to 1998, a total of 29 astrocytic tumor of all grades obtained by operative resection were included for evaluation. We studied the expression of $p27^{kip1}$ protein immunohistochemical assay in astrocytic tumors and compared the findings with the clinicopathologic parameters. Immunohistochemical staining was performed on formalin-fixed paraffin-embedded sections by the avidin-biotin-peroxidase complex method. According to WHO classification, all cases were divided into astrocytomas(4 cases), anaplastic astrocytomas(9 cases), and glioblastomas(16 cases) by 3 pathologists. Clinical information was obtained from medical records, and others such as location and size of tumors from imaging studies. Results : Mean $p27^{kip1}$ protein labeling indexes(LI, mean${\pm}$standard deviation) of astrocytomas, anaplastic astrocytomas, and glioblastomas were $80.6{\pm}9.1$, $63.6{\pm}21.0$, and $28.9{\pm}18.7$, respectively, and were inversely correlated with grade of glial tumors(p<0.0001). Mean $p27^{kip1}$ protein LI in the recurrent group was lower than that in the nonrecurrent group, but there was no significant difference statistically(p=0.464). Additionally, $p27^{kip1}$ protein expression did not show any significant relationship to other prognostic factors such as age(p=0.1643), tumor size(p=0.8), or location(p=0.8). Conclusion : These results suggested that reduced expression of $p27^{kip1}$ protein may play a important role in the malignant transformation process of astrocytic tumor cells.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.8
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• pp.1003-1007
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• 2009

To develop Allium tuberosum L. as a cancer preventive food material, thiosulfinates and biological active components were isolated from Allium tuberosum L. and the apoptotic effects of thiosulfinates in human cancer cells were examined. Thiosulfinates decreased viable cell numbers in dose- and time-dependent manners. Thiosulfinates at the 20 $\mu g$/mL concentration inhibited more than 60% cell proliferation in HepG2 and A549 human cancer cells, respectively. Also the morphology of cells treated with thiosulfinates of 30 $\mu g$/mL concentration was distorted with shrunken cell mass while the cell number was lower than that of control cells. The $IC_{50}$ values in the HepG2 cells were higher than those of the A549 cells. Thiosulfinates at the 30 $\mu g$/mL concentration showed the formation of apoptotic bodies and a nuclear condensation, and an increase in the cell populations of the sub-G1 phase in the HepG2 cells. These results indicate that thiosulfinates from Allium tuberosum L. inhibited cell proliferation in HepG2 via apoptosis.

• Journal of KIISE:Software and Applications
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• v.31 no.9
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• pp.1233-1245
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• 2004

Though biometrics to authenticate a person is a good tool in terms of security and convenience, typical authentication algorithms using biometrics may not be executed on resource-constrained devices such as smart cards. Thus, to execute biometric processing on resource-constrained devices, it is desirable to develop lightweight authentication algorithm that requires only small amount of memory and computation. Also, among biological features, face is one of the most acceptable biometrics, because humans use it in their visual interactions and acquiring face images is non-intrusive. We present a new face authentication algorithm in this paper. Our achievement is two-fold. One is to present a face authentication algorithm with low memory requirement, which uses support vector machines (SVM) with the feature set extracted by genetic algorithms (GA). The other contribution is to suggest a method to reduce further, if needed, the amount of memory required in the authentication at the expense of verification rate by changing a controllable system parameter for a feature set size. Given a pre-defined amount of memory, this capability is quite effective to mount our algorithm on memory-constrained devices. The experimental results on various databases show that our face authentication algorithm with SVM whose input vectors consist of discriminating features extracted by GA has much better performance than the algorithm without feature selection process by GA has, in terms of accuracy and memory requirement. Experiment also shows that the number of the feature ttl be selected is controllable by a system parameter.

• Journal of KIISE:Software and Applications
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• v.28 no.9
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• pp.669-680
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• 2001

Genetic Algorithms are optimization algorithm that mimics biological evolution to solve optimization problems. Genetic algorithms provide an alternative to traditional optimization techniques by using directed random searches to locate optimal solutions in complex fitness landscapes. Hybrid genetic algorithm that is combined with local search called learning can sustain the balance between exploration and exploitation. The genetic traits that each individual in the population learns through evolution are transferred back to the next generation, and when this learning is combined with genetic algorithm we can expect the improvement of the search speed. This paper proposes a genetic algorithm based Cellular Learning with accelerated learning capability for function optimization. Proposed Cellular Learning strategy is based on periodic and convergent behaviors in cellular automata, and on the theory of transmitting to offspring the knowledge and experience that organisms acquire in their lifetime. We compared the search efficiency of Cellular Learning strategy with those of Lamarckian and Baldwin Effect in hybrid genetic algorithm. We showed that the local improvement by cellular learning could enhance the global performance higher by evaluating their performance through the experiment of various test bed functions and also showed that proposed learning strategy could find out the better global optima than conventional method.

• Korean Journal of Pharmacognosy
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• v.39 no.4
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• pp.310-315
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• 2008

Viscum album coloratum (Korean mistletoe; KM) is a semi-parasitic plant growing on various trees. This plant hasbeen shown to possess a variety of biological functions such as immunomodulation, apoptosis-induction and antitumor activity. However, there is no information about how the extract of KM affects life span of the host. In this study, in order to examine the effect of KM on the longevity of the host, we investigated whether a Korean mistletoe extract (KME) was able to extend the life length in an experimental model using the spring silkworm moth of Bombyx mori (Lepidoptera bombycidae). We established a model test for survival in which all of the male and female moths died within 18 days after the beginning of the experiment. Mean survival time of female moths was longer than that of male moths. Both male and female moths fed with KME containing diet (200 or 400 ${\mu}g$/head/day) showed significantly higher mean survival times than those of the control moths. Studying the effect of KME on prolongation of mean survival time showed that male moths were more susceptible than female moths. The moths fed with KME-containing diet showed a slight decrease in body weight. Interestingly, however, no difference in food intake was observed between moths fed with KME-containing diet and those with control diet. In analysis for mRNA increase in the SIRT2 gene, a member of the Sir2 gene family playing important roles in regulation of cell death and prolongation of life span, moths fed with KME-containing diet showed a significant increase in SIRT2 gene expression. These results suggest that KME has a potential to extend the life span in Bombyx mori, and its effect is partly associated with increase in SIRT2 gene expression.

• Journal of the Korean association of regional geographers
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• v.12 no.6
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• pp.645-655
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• 2006

Apsan, as part of the main ecosystem of Daegu city, plays an important role for maintaining the environmental sustainability of the large city. Especially varieties of valuable resources, which are cultural, historical, biological, geomorphological and geological, are distributed around Apsan. Therefore the positive preservation plan is required. This paper aims to examine the environmental characteristics of Apsan and then suggests the following ideas for the environmental preservation and sustainable use of Apsan. 1) 'The New Map of Apsan' that includes more exact information needs to be produced. 2) The Apsan ecosystem management plan should be made under the precision natural ecology investigation. 3) For the protection of inanimate object resources, such as geographical feature and geology, the Geotourism Department needs to be established within Daegu metropolitan office of education or the tourism division of Daegu city government. 4) An effective environmental-impact-assessment system should be officially established. 5) the positive administrative and financial support system led by local NGOs is required for the Apsan environmental protection activities and education. 6) It is necessary to bring out into the open prayer sites to prevent forest fire. 7) 'The nature rest year system' enforcement is required to restore the damaged ecological space of Apsan.

• Journal of Biomedical Engineering Research
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• v.19 no.6
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• pp.571-575
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• 1998

One of the most significant features of diagnostic ultrasonic instruments is to provide real time information of the soft tissues movements. Echocardiogram has been widely used for diagnosis of heart diseases since it is able to show real time images of heart valves and walls. However, the currently used ultrasonic images are deteriorated due to presence of speckle noises and image dropout. Therefore, it is very important to develop a new technique which can enhance ultrasonic images. In this study, a technique which extracts enhanced binary images in echocardiograms was proposed. For this purpose, a digital moving image file was made from analog echocardiogram, then it was stored as 8-bit gray-level for each frame. For an efficient image processing, the region containing the heat septum and tricuspid valve was selected as the region of interest(ROI). Image enhancement filters and morphology filters were used to reduce speckle noises in the images. The proposed procedure in this paper resulted in binary images with enhanced contour compared to those form the conventional threshold technique and original image processing technique which can be further implemented for the quantitative analysis of the left ventricular wall motion in echocardiogram by easy detection of the heart wall contours.

• Journal of Biomedical Engineering Research
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• v.19 no.6
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• pp.551-562
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• 1998

Amultiresolution filtering algorithm based on the physical SPECT lesion detachability provides and optimal solution for SPECT reconstruction problem. Related to the previous study, we estimated the SPECT lesion detection capability by m minimum detectable lesion sizes (MDLSs), and generated m reconstruction filters which are designed to maximize the smoothing effect at a fixed MDLS-dependent resolution level $\frac{MDLS}{4\sqrt{2In2}}$. The proposed multiresolution filtering algorithm used a coarse-to-fine approach for the m-level resolution filter images obtained from these m filters for a given projection image. First, the local homogeneity is determined for every pixel of the filter images, by comparing the local variance value computed in a window centered at the pixel and the mode determined from the distribution of the local variances. Based on the local homogeneity, the pixels declared as homogeneous are chosen from the filter image of the lowest resolution, and for the other pixels the same process is repeated for the higher resolution filter images. For the non-homogeneous pixels after this pixels after this repetition process ends, the pixel values of the highest resolution filter image are substituted. From the results of the simulated experiments, the proposed multiresolution filtering algorithm showed a strong smoothing effect in the homogeneous regions and a significant resolution improvement near the edge regions of the projection images, and so produced good adaptability effects in the reconstructed images.