• Applied Microscopy
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• v.39 no.4
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• pp.333-340
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• 2009

In the present study, ultrastructural features of the mesophyll tissue have been investigated in Crassulacean acid metabolism (CAM)-performing succulent Orostachys. A large central vacuole and numerous small vacuoles in the peripheral cytoplasm were characterized at the subcellular level in both developing and mature mesophyll cells. The most notable feature was the invagination of vacuolar membranes into the secondary vacuoles or multivesicular bodies. In many cases, tens of single, membrane-bound secondary vacuoles of various sizes were found to be formed within the central vacuole. multivesicular bodies containing numerous small vesicles were also distributed in the cytoplasm but were better developed within the central vacuole. Occasionally, electron-dense prevacuolar compartments, directly attached to structures appearing to be small vacuoles, were also detected in the cytoplasm. One or more huge central vacuoles were frequently observed in cells undergoing differentiation and maturation. Consistent with the known occurrence of morphologically distinct vacuoles within different tissues, two types of vacuoles, one representing lytic vacuoles and the other, most likely protein storage vacuoles, were noted frequently within Orostachys mesophyll. The two types coexisted in mature vegetative cells but did not merge during the study. Nevertheless, the coexistence of two distinct vacuole types in maturing cells implies the presence of more than one mechanism for vacuolar solute sorting in these species. The vacuolar membrane is known to be unique among the intracellular compartments for having different channels and/or pumps to maintain its function. In CAM plants, the vacuole is a very important organelle that regulates malic acid diurnal fluctuation to a large extent. The membrane invagination seen in Orostachys mesophyll likely plays a significant role in survival under the physiological drought conditions in which these Orostachys occur; by increasing to such a large vacuolar volume, the mesophyll cells are able to retain enormous amounts of acid when needed. Furthermore, the mesophyll cells are able to attain their large sizes with less energy expenditure in order to regulate the large degree of diurnal fluctuation of organic acid that occurs within the vacuoles of Orostachys.

• Korean Journal of Ecology and Environment
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• v.44 no.3
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• pp.253-263
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• 2011

This study was conducted to gain preliminary data for restoration and management of constructed small-scale ponds in paddy fields through analysis of their physicochemical and biological properties. A field survey was performed at 13 small-scale ponds located in paddy fields from August 2009 to October 2010. Structural properties, water quality, soil characteristics and fish fauna were measured. Results showed that small-scale ponds without frames might lose their function over time because of crumbling walls. Therefore, it is necessary for these ponds to have frames for soil protection and sustainable maintenance. Chemical oxygen demand (COD), total nitrogen (TN) and total phosphorus (TP) concentration were higher than the water quality standard for agricultural water in small-scale ponds. In particular, TN concentration was 8.03 mg $L^{-1}$ and over 8 times the water quality standard because of the presence of livestock such as cows and pigs in the study areas. Sand, organic matter and available phosphorus contents of soil in small-scale ponds was 53.4${\pm}$16.6%, 21.8${\pm}$9.74 g $kg^{-1}$ and 12.8${\pm}$7.59 mg $kg^{-1}$, respectively indicating that sand and available phosphorus contents were suitable for plants in small-scale ponds, but organic matter contents was somewhat low in newly constructed small-scale ponds, and would take some time to stabilize for plant growing. Fish fauna was not diverse with only 4 species at all sites surveyed. Collected fishes share a common feature that they all inhabit paddy fields or canals with shallow water depth. In this study, all ponds were not linked to the streams and canals around them. It appears that connection to adjacent streams was the major factor controlling fish fauna in small-scale ponds. The results of statistical analysis were classified into three groups. Factor 1 was 26.3%, which shows a structural properties such as area and depth of small-scale pond. As for factor 2, it appears on 20.1%, showing water quality like a TP, suspended solids (SS) and COD. Small-scale ponds were classified into three groups by factor scores. Group I consisted of 6 small-scale ponds, which were larger than the others. Group III had higher water quality than the others. We conclude that the most important points to be considered for restoration and management of small-scale ponds is connection with adjacent streams or ditches and depth and size of the small-scale pond.

• Korean Journal of Biological Psychiatry
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• v.9 no.1
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• pp.50-61
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• 2002

Objectives:High nailfold plexus visibility can reflect central nervous system defects as an etiologic factor of schizophrenia indirectly. Previous studies suggest that this visibility is particularly related to the negative symptoms of schizophrenia and frontal lobe deficiency. In this study, we examined the relationships between nailfold plexus visibility, and various clinical variables and neuropsychological functions in schizo-phrenic patients. Methods:Forty patients(21males, 19 females) satisfying the DSM-IV criteria for schizophrenia and thirty eight normal controls(20 males, 18 females) were measured for Plexus Visualization Score(PVS) by using the capillary microscopic examination. For the assessment of psychopathology, process-reactivity, premorbid adjustment, and neuropsychological functions, we used Positive and Negative Syndrome Scale(PANSS), Ullmann-Giovannoni Process-Reactive Questionnaire(PRQ), Phillips Premorbid Adjustment Scale(PAS), Korean Wechsler Adult Intelligence Scale(KWIS), Continuous Performance Test(CPT), Wisconsin Card Sort Test (WCST), and Word Fluency Test. We also collected data about clinical variables. Results:PVS was correlated with PANSS positive symptom score and composite score negatively. There were no correlations between PVS and PRQ score, PAS score and neuropsychological variables respectively. Conclusions:This study showed that nailfold plexus visibility was a characteristic feature in some schizophrenic patients, and that higher plexus visibility was associated with the negative symptoms of schizophrenia. There was no association between plexus visibility and neuropsychological functions.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.4
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• pp.223-231
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• 2012

The purpose of this study is to investigate basically the mechanism of heat transfer by the resolution of complex fluid flow inside a sophisticated designed screw dryer for the treatment of sewage sludge by using numerical analysis and experimental study. By doing this, the result was quite helpful to obtain the design criteria for enhancing drying efficiency, thereby achieving the optimal design of a multiple screw type dryer for treating inorganic and organic sludge wastes. One notable design feature of the dryer was to bypass a certain of fraction of the hot combustion gases into the bottom of the screw cylinder, by the fluid flow induction, across the delicately designed holes on the screw surface to agitate internally the sticky sludges. This offers many benefits not only in the enhancement of thermal efficiency even for the high viscosity material but also greater flexibility in the application of system design and operation. However, one careful precaution was made in operation in that when distributing the hot flue gas over the lump of sludge for internal agitation not to make any pore blocking and to avoid too much pressure drop caused by inertial resistance across the lump of sludge. The optimal retention time for rotating the screw at 1 rpm in order to treat 200 kg/hr of sewage sludge was determined empirically about 100 minutes. The corresponding optimal heat source was found to be 150,000 kcal/hr. A series of numerical calculation is performed to resolve flow characteristics in order to assist in the system design as function of important system and operational variables. The numerical calculation is successfully evaluated against experimental temperature profile and flow field characteristics. In general, the calculation results are physically reasonable and consistent in parametric study. In further studies, more quantitative data analyses such as pressure drop across the type and loading of drying sludge will be made for the system evaluation in experiment and calculation.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.1
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• pp.23-30
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• 2007

The ultimate objective of this study is to develop oxygen-enriched combustion techniques applicable to the system of practical industrial boiler. To this end the combustion characteristics of lab-scale LNG combustor were investigated as a first step using the method of numerical simulation by analyzing the flame characteristics and pollutant emission behaviour as a function of oxygen enrichment level. Several useful conclusions could be drawn based on this study. First of all, the increase of oxygen enrichment level instead of air caused long and thin flame called laminar flame feature. This was in good agreement with experimental results appeared in open literature and explained by the effect of the decrease of turbulent mixing due to the decrease of absolute amount of oxidizer flow rate by the absence of the nitrogen species. Further, as expected, oxygen enrichment increased the flame temperatures to a significant level together with concentrations of $CO_2$ and $H_2O$ species because of the elimination of the heat sink and dilution effects by the presence of $N_2$ inert gas. However, the increased flame temperature with $O_2$ enriched air showed the high possibility of the generation of thermal $NO_x$ if nitrogen species were present. In order to remedy the problem caused by the oxygen-enriched combustion, the appropriate amount of recirculation $CO_2$ gas was desirable to enhance the turbulent mixing and thereby flame stability and further optimum determination of operational conditions were necessary. For example, the adjustment of burner with swirl angle of $30\sim45^{\circ}$ increased the combustion efficiency of LNG fuel and simultaneously dropped the $NO_x$ formation.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.7
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• pp.694-699
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• 2008

Considering the severe regulation associated with sludge treatment such as direct landfill and ocean dumping, there is no doubt in that an advanced study for the proper treatment of sludge is urgently needed in near feature. As one of viable method for sludge treatment, fry-drying of sludge by waste oil has been investigated in this study. The fundamental mechanism of this drying method lies in the phenomenon of rapid moisture escape in the sludge pore toward oil media. This is caused by the severe pressure gradient formed by the rapid oil heating between sludge and oil. As part of research effort of fry-drying using waste oil, a series of basic study has been made experimentally to obtain typical drying curves as function of important parameters such as drying temperature, drying time, oil type and geometrical shape of sludge formed. Based on this study, a number of useful conclusion can be drawn as following. The fry-drying method by oil immersion was found quite effective in the removal efficiency of sludge moisture, in general, the moisture content decreases significantly after 10 minutes and the whole moisture content was less than 5% after 14 minutes regardless of the drying temperature. The increase of oil temperature up to 140$^{\circ}C$ favors significantly for the removal of moisture but there was no visible difference above 140$^{\circ}C$. As expected, the decrease of diameter in sludge was efficient in drying due to the increased surface area per unit volume. Further, the effect of oil property by the change of oil type was noted. To be specific, for the case of engine oil the efficiency was found to be remarkably delayed in moisture evaporation compared with that of vegetable oil due to the increased viscosity of engine oil. It produced a result of increasing the evaporation of moisture largely relatively high in the drying temperature over 140$^{\circ}C$ compared with the drying temperature 120$^{\circ}C$ drying temperature as the drying time passed. Accordingly, the drying temperature is considered desirable as keeping over 140$^{\circ}C$ regardless of a sort of used oil.

• Journal of Intelligence and Information Systems
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• v.17 no.4
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• pp.241-254
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• 2011

Financial time-series forecasting is one of the most important issues because it is essential for the risk management of financial institutions. Therefore, researchers have tried to forecast financial time-series using various data mining techniques such as regression, artificial neural networks, decision trees, k-nearest neighbor etc. Recently, support vector machines (SVMs) are popularly applied to this research area because they have advantages that they don't require huge training data and have low possibility of overfitting. However, a user must determine several design factors by heuristics in order to use SVM. For example, the selection of appropriate kernel function and its parameters and proper feature subset selection are major design factors of SVM. Other than these factors, the proper selection of instance subset may also improve the forecasting performance of SVM by eliminating irrelevant and distorting training instances. Nonetheless, there have been few studies that have applied instance selection to SVM, especially in the domain of stock market prediction. Instance selection tries to choose proper instance subsets from original training data. It may be considered as a method of knowledge refinement and it maintains the instance-base. This study proposes the novel instance selection algorithm for SVMs. The proposed technique in this study uses genetic algorithm (GA) to optimize instance selection process with parameter optimization simultaneously. We call the model as ISVM (SVM with Instance selection) in this study. Experiments on stock market data are implemented using ISVM. In this study, the GA searches for optimal or near-optimal values of kernel parameters and relevant instances for SVMs. This study needs two sets of parameters in chromosomes in GA setting : The codes for kernel parameters and for instance selection. For the controlling parameters of the GA search, the population size is set at 50 organisms and the value of the crossover rate is set at 0.7 while the mutation rate is 0.1. As the stopping condition, 50 generations are permitted. The application data used in this study consists of technical indicators and the direction of change in the daily Korea stock price index (KOSPI). The total number of samples is 2218 trading days. We separate the whole data into three subsets as training, test, hold-out data set. The number of data in each subset is 1056, 581, 581 respectively. This study compares ISVM to several comparative models including logistic regression (logit), backpropagation neural networks (ANN), nearest neighbor (1-NN), conventional SVM (SVM) and SVM with the optimized parameters (PSVM). In especial, PSVM uses optimized kernel parameters by the genetic algorithm. The experimental results show that ISVM outperforms 1-NN by 15.32%, ANN by 6.89%, Logit and SVM by 5.34%, and PSVM by 4.82% for the holdout data. For ISVM, only 556 data from 1056 original training data are used to produce the result. In addition, the two-sample test for proportions is used to examine whether ISVM significantly outperforms other comparative models. The results indicate that ISVM outperforms ANN and 1-NN at the 1% statistical significance level. In addition, ISVM performs better than Logit, SVM and PSVM at the 5% statistical significance level.

• Journal of Gastric Cancer
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• v.4 no.4
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• pp.207-212
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• 2004

Purpose: Invasion and metastasis in solid tumors require the action of tumor-associated proteases. The serine protease urokinase-type plasminogen (uPA) and receptor (uPAR) appear to have a major function in these processes. Expression of the uPAR is elevated in breast and colon carcinomas, and this is often associated with invasiveness and poor prognosis. The purpose of this study was to determine whether the expression of the uPAR gene correlates with clinico-pathological parameters in human gastric carcinomas. Materials and Methods: We examined the expression of uPAR mRNA by using northern blot analysis and RT-PCR in 35 gastric carcinomas and the surrounding normal mucosa. Macroscopic and histopathological tumor findings and survival rates were obtained from the patient records and from endoscopic, surgical, and pathological reports. Results: The expression of uPAR and was higher in most neoplasms than in the corresponding normal mucosal tissue. uPAR mRNA expression in tumors correlated well with lymph-node metastasis (P<0.02) and tumor stage (P<0.01). The survival rate of patients with tumors displaying high uPAR expression levels was significantly lower (P<0.04) than that of patients without uPAR expression, but IL-8 showed only the tendency of survival difference. Conclusion: These results suggest that uPAR may be an important prognostic factor in human gastric carcinomas.

• The Korean Journal of Malacology
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• v.24 no.3
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• pp.229-241
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• 2008

Changes of growth and histopathological feature in the mantle structure of the equilateral venus, Gomphina veneriformis exposed to tribultyltin chloride (TBTCl) for 36 weeks were observed. Concentrations of TBTCl were 0, 0.4, 0.6, and $0.8{\mu}g/L$. A regression analysis by power function of SPSS was shown that the growth of experimental groups was significantly decreased after 12 weeks of exposure. For histological analysis, mantle tissues were characterized using H-E stain, AB-PAS (pH 2.5) reaction and Masson's trichrome stain, and epidermal layer thickness and mucous cell distribution were analysed using the image analyser. The mantle had 4-folds (inner-inner, inner-outer, middle, and outer) and its epidermal layer consisted of simple epithlia. A periostracum was observed in the periostracal groove between middle and outer fold. Inner epidermal layer consisted of simple ciliated columnar epithelia, but the outer epidermal layer consisted of simple non-ciliated columnar epithelia. Alcian blue positive mucous cells showed blue color (7462c, 653c) in the inner fold, violet color (2583c) in the middle fold, and blue color (647c, 7455c) in inner epidermal layer (numbers in the parenthesis are codes of Pantone process coated color). Hemolymph sinus in the mantle was extended, and mucous cells in inner plica of the middle fold were stained as blue (7455c) and violet (2587c), after 12 weeks of TBTCI exposure. Cilia and striated border were disappeared, and number of mucous cells in the inner epidermal layer was reduced. Serious histopathological changes in middle and outer fold near the periostracum were observed after 36 weeks. Moreover, epidermal layer thickness and mucous cell distribution were showed decreasing tendency as exposure time to TBTCI was increased. Results of this study suggested that TBTCl induced growth disorder with histopathological changes.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.32 no.3
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• pp.154-167
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• 2014

The results of this study conducted to identify the substance, regional characteristics or landscaping of Namwon Yonghogugok, which is the only valley of Jiri Mountain, based on Kim Samun's 'Yonghokugok-Gyeongseungannae(龍湖九曲景勝案內)', 'Yongseongji(龍城誌)' and position, meaning of letters carved and projection technique by ArcGIS10.0 on the rocks are as below. The feature landscapes of the canyon of Yonghogugok, which is an incised meander and one of the Eight beautiful scenery of Namwon, ponds, cliffs and rocks generated with metamorphic rocks and granites weathered by rapids torrents. As a result of measuring the GPS coordinates of the letters carved on the rocks, excluding the 3 Gok Hakseoam and the distances based on the origin and destination of the letters carved on the rocks using the API(Application Programming Interface) function of Daum map, the total distance of Yonghogugok was 3.5km and the average distance between the each Gok was 436.5m. It is assumed that Yonghogugok was designated by Sarim(士林) of the Kiho School(畿湖學派) related to Wondong Hyangyak(元洞鄕約) which is the main agent of Yonghojeongsa(龍湖精舍), the forerunner of Yonghoseowon(龍湖書院), between the late Joseon Dynasty and the early Japanese colonial era, in 1927. Its grounds are the existence of Yonghoyeongdang mentioned on 'Yonghojeongsilgi'(龍湖亭實記), records of 'Haeunyugo(荷隱遺稿)', 'Yonghopumje(龍湖品題)' of Bulshindang(佛神堂), 'Yonghojeongsadonggu Gapjachun(龍湖精舍洞口 甲子春)' letters carved on the rocks and 'Yonghogugok-Shipyeong(龍湖九曲十詠)' posted on Mokgandang of Yonghoseowon. Comprehensively considering the numerous poetry society lists carved on the stone wall of Punghodae(風乎臺), the Sixth Gok Yuseondae, its stone mortar, 'Bangjangjeildongcheon(方丈第一洞天)' of Bulshindang and Gyoryongdam(交龍潭), the Yonghoseokmun(龍湖石門) letters carved on the rocks, Yeogungseok adjacent to the First Gok and Fengshui facilities, centered on Yonghoseowon and Yonghojeong, Yonghogugok can be understood as a unique valley culture formed with the thoughts of Confucianism, Buddhism, Taoism and Fengshui. 'Yonghogugok-Gyeongseungannae' provides very useful information to understand the place name, called by locals and landscaping aspects of Yonghogugok in the late Joseon Dynasty. In addition, the meaning of "Nine dragons" and even though 12 chu(湫: pond) of Yonghogugok Yongchudong including Bulyeongchu, Guryongchu, Isuchu, Goieumchu and Daeyachu are mentioned on Yongseongji, a part of them cannot be confirmed now. Various place names and facilities relevant to Guryong adjacent to Yonghogugok are the core of the place identity. In addition, the accurate location identification and the delivery of the landscaping significance of the 12 ponds is expected to provide landscaping attractiveness of Yonghogugok and become very useful contents for landscaping storytelling and a keyword of storyboard.