• Journal of Ecology and Environment
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• v.44 no.1
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• pp.8-25
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• 2020

Background: Species of the genera Eucalyptus, Cupressus, and Pinus are the most widely planted tree species in the country in general and in Chilimo dry Afromontane forest in particular. Eucalyptus covers 90% of the total planted forest area in the country. However, only limited information exists in the country regarding aboveground biomass (AGB), belowground biomass (BGB), growth, and yield. This study was conducted to assess the variables on 25 and 30 years of age for three planted species: Cupressus lusitanica, Eucalyptus saligna, and Pinus patula in Chilimo plantation forest, in the Central Highlands of Ethiopia. A two-times inventory was conducted in 2012 and 2017. A total of nine square sampled plots of 400 ㎡ each, three plots under Cupressus lusitanica, 3 Eucalyptus saligna, and 3 Pinus patula were used for data collection. Data on height, diameter, soil, and tree stumps were collected. Percent C, % N, and bulk density was performed following chemical procedure. Results: The aboveground biomass ranged from 125.76 to 228.67 t C ha^-1 and the basal area and number of stems from 3.76 to 25.50 ㎡ ha^-1 and 483 to 1175 N ha^-1, respectively. The mean annual basal area and volume increment were between 0.97 and 1.20 ㎡ ha^-1 year^-1 and 10.79 and 16.22 ㎥ ha^-1 year^-1. Both carbon and nitrogen stock of the planted forest was non-significant among the tree species. Conclusion: The aboveground biomass, growth, and yield significantly varied among the species. Cupressus lusitanica had the highest aboveground biomass, volume, and basal area, while Eucalyptus saligna had the lowest value. To a depth of 1 m, total carbon stored ranged from 130.13 to 234.26 t C ha^-1. The total annual carbon sequestration potential was 12,575.18 t CO₂ eq. Eucalyptus has the highest carbon stock density and growth rate than other species.

• Journal of the Korean Association of Geographic Information Studies
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• v.17 no.4
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• pp.101-111
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• 2014

Spatial events are predictable using data mining classification algorithms. Decision trees have been used as one of representative classification algorithms. And they were normally used in the classification tasks that have label class values. However since using rule ranking methods, spatial prediction have been applied in the spatial prediction problems. This paper compared rule ranking methods for the spatial prediction application using a decision tree. For the comparison experiment, C4.5 decision tree algorithm, and rule ranking methods such as Laplace, M-estimate and m-branch were implemented. As a spatial prediction case study, landslide which is one of representative spatial event occurs in the natural environment was applied. Among the rule ranking methods, in the results of accuracy evaluation, m-branch showed the better accuracy than other methods. However in case of m-brach and M-estimate required additional time-consuming procedure for searching optimal parameter values. Thus according to the application areas, the methods can be selectively used. The spatial prediction using a decision tree can be used not only for spatial predictions, but also for causal analysis in the specific event occurrence location.

• Journal of the Institute of Convergence Signal Processing
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• v.2 no.4
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• pp.9-15
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• 2001

In this paper we investigate context dependent acoustic models to improve the performance of the Korean speech recognition . The algorithm are using the Korean phonological rules and decision tree, By Successive State Splitting(SSS) algorithm the Hidden Merkov Netwwork(HM-Net) which is an efficient representation of phoneme-context-dependent HMMs, can be generated automatically SSS is powerful technique to design topologies of tied-state HMMs but it doesn't treat unknown contexts in the training phoneme contexts environment adequately In addition it has some problem in the procedure of the contextual domain. In this paper we adopt a new state-clustering algorithm of SSS, called Phonetic Decision Tree-based SSS (PDT-SSS) which includes contexts splits based on the Korean phonological rules. This method combines advantages of both the decision tree clustering and SSS, and can generated highly accurate HM-Net that can express any contexts To verify the effectiveness of the adopted methods. the experiments are carried out using KLE 452 word database and YNU 200 sentence database. Through the Korean phoneme word and sentence recognition experiments. we proved that the new state-clustering algorithm produce better phoneme, word and continuous speech recognition accuracy than the conventional HMMs.

• Tuberculosis and Respiratory Diseases
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• v.58 no.6
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• pp.600-606
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• 2005

Background : The development of bronchoscopic equipment along with the precision of radiographic techniques had reduced the mortality rate of patients with tracheobronchial foreign bodies but has been no change in the incidence of tracheobronchial foreign bodies since their introduction. The aim of this study was to assess the clinical characteristics of a tracheobronchial foreign body aspiration and to evaluate the efficacy of the treatment modality in children and adults. Methods : This is a retrospective review of 64 patients who underwent bronchoscopic procedures for the treatment of aspirated foreign bodies from December 1994 through March 2004 at the Chonnam national university hospital. Results : There were 47 males and 17 females, aged from 1 month to 78 years. Most of the patients had no underlying illness except for one patient with a cerebrovascular accident that contributed to the foreign body aspiration. The most common symptom was cough, which was noted in 54 patients (84.3%). The other presenting symptoms were dyspnea (48.8%), fever (20.3%), sputum (14%), vomiting (7.8%), and chest pain (4.6%). Those whose tracheobronchial foreign bodies were diagnosed more than 2 days after the aspiration (21 patients) were more likely to have pneumonia than those whose foreign bodies were diagnosed within 2 days (p = 0.009). Foreign bodies were visualized in the plain chest radiographs in 12 cases (18.8%), while others showed air trapping (21, 32.8%), pneumonia (15, 23.4%), atelectasis (7, 10.9%), and normal findings (9, 14.1%). The foreign bodies were more frequently found in the right bronchial tree (36) compared with the left bronchial tree (22, p = 0.04). In order to remove the foreign bodies, twenty (31.2%) cases were removed using flexible bronchoscopy, while 42 (65.6%) and 2 (3.2%) cases required rigid bronchoscopy and surgery, respectively. Conclusions : Tracheobronchial Foreign body aspiration had a bimodal age distribution in the infancy and old age around 60 years. They were found more frequently in the right bronchial tree. In addition, patients whose foreign bodies were diagnosed more than 2 days after the aspiration were more likely have a infection. Rigid bronchoscopy is the procedure of choice for uncooperative children and for those with foreign bodies lodged deeply in the small bronchial tree.

• Journal of Environmental Health Sciences
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• v.44 no.3
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• pp.217-226
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• 2018

Objectives: Despite the positive effects of Off-site risk assessment (ORA) system such as prevention of chemical accidents, some problems have been constantly raised. The purpose of this study is to analyze the problems that have occurred through the implementation of the ORA system for the past three years and to suggest reasonable directions for improvement in the future. Methods: In order to identify the problems with the methodology and procedure of ORA system, we analyzed statutes, administrative rules and documents related to the ORA system. A survey of ORA reviewers in National Institute of Chemical Safety was conducted to investigate the weight of determinants considered when judging the level of total risk in ORA. Results: In this study, we found out the uncertainty of the estimation of the number of people in the impact range in the procedure of the risk assessment of individual handling facilities, the lack of quantitative risk analysis methods for environmental receptors, and the ambiguity of the criteria for the total risk. In addition to suggesting solutions to the problems mentioned above, we also, suggested a decision tree for total risk in ORA. Conclusion: We anticipate that the solutions including the systematic decision tree for total risk suggested will contribute to the smooth operation of the ORA system.

• Journal of Internet Computing and Services
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• v.14 no.4
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• pp.25-33
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• 2013

The procedure of the arbitration which is the tag collision is essential because the multiple tags response simultaneously in the same frequency to the request of the Reader. This procedure is known as Anti-collision and it is a key technology in the RFID system. In this paper, we propose the 4-Bit Pattern Slot Allocation(4-BPSA) algorithm for the high-speed identification of the multiple tags. The proposed algorithm is based on the tree algorithm using the time slot and identify the tag quickly and efficiently through accurate prediction using the a slot as a 4-bit pattern according to the slot allocation scheme. Through mathematical performance analysis, We proved that the 4-BPSA is an O(n) algorithm by analyzing the worst-case time complexity and the performance of the 4-BPSA is improved compared to existing algorithms. In addition, we verified that the 4-BPSA is performed the average 0.7 times the query per the Tag through MATLAB simulation experiments with performance evaluation of the algorithm and the 4-BPSA ensure stable performance regardless of the number of the tags.

• Spatial Information Research
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• v.18 no.3
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• pp.23-32
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• 2010

LIDAR data are useful for forest applications such as bare-earth DEM generation for forest areas, and estimation of tree height and forest biomass. As a core preprocessing procedure for most forest applications, this study attempts to develop an efficient method to detect forest areas from LIDAR data. First, we suggest three perceptual cues based on multiple return characteristics, height deviation and spatial distribution, being expected as reliable perceptual cues for forest area detection from LIDAR data. We then classify the potential forest areas based on the individual cue and refine them with a bi-morphological process to eliminate falsely detected areas and smoothing the boundaries. The final refined forest areas have been compared with the reference data manually generated with an aerial image. All the methods based on three types of cues show the accuracy of more than 90%. Particularly, the method based on multiple returns is slightly better than other two cues in terms of the simplicity and accuracy. Also, it is shown that the combination of the individual results from each cue can enhance the classification accuracy.

• Journal of KIISE:Computing Practices and Letters
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• v.16 no.5
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• pp.531-540
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• 2010

In this paper, we present a two-phase shallow semantic parsing method based on a maximum entropy model. The first phase is to recognize semantic arguments, i.e., argument identification. The second phase is to assign appropriate semantic roles to the recognized arguments, i.e., argument classification. Here, the performance of the first phase is crucial for the success of the entire system, because the second phase is performed on the regions recognized at the identification stage. In order to improve performances of the argument identification, we incorporate syntactic knowledge into its pre-processing step. More precisely, boundaries of the immediate clause and the upper clauses of a predicate obtained from clause identification are utilized for reducing the search space. Further, the distance on parse trees from the parent node of a predicate to the parent node of a parse constituent is exploited. Experimental results show that incorporation of syntactic knowledge and the separation of argument identification from the entire procedure enhance performances of the shallow semantic parsing system.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.37 no.2
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• pp.50-59
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• 2000

Stereo vision is a technique extracting depth information from stereo images, which are two images that view an object or a scene from different locations. The most important procedure in stereo vision, which is called stereo matching, is to find the same points in stereo images. It is difficult to match stereo images in real time because stereo matching requires heavy calculation. In this Paper we design a digital VLSI to Process stereo matching in real time, which we call stereo image match processor (SIMP). For implementation of real time stereo matching, sliding memory and minimum selection tree are presented. SIMP is designed with pipeline architecture and parallel processing. SIMP takes 64 gray level 64$\times$64 stereo images and yields 8 level 64 $\times$64 disparity map by 3 bit disparity and 12 bit address outputs. SIMP can process stereo images with process speed of 240 frames/sec.

• Journal of the Korean Institute of Landscape Architecture
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• v.28 no.5
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• pp.26-38
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• 2000

The purpose of this study is to perform a comparative analysis on landscape ordinances between Korea and U.S.A to find out some useful implications for remedial devices on Korean landscape ordinances in terms of their legislation, contents, and operating procedure. The results of this study are as follows; 1) Technical issues addressed by the U.S.A landscape ordinances may be divided broadly into five items(landscaping, planting, facilities, land use, preservation and protection) and subdivided diversely by each item. 2) The thirty four landscape ordinances of U.S.A., collected for this study, were made up of the nineteen comprehensive landscape ordinances(56%), the nine tree ordinances(26%) and the six post construction landscape ordinances(18%) s a result classifying into three types(comprehensive, post-construction, and tree ordinances) of landscape ordinances. 3) The differences in the view of the legislation, contents and practical process in the Korea and the U.S.A. landscape ordinances were to be analyzed comparatively. 4) Whether or not of applying the thirty four landscape ordinances of U.S.A. to the domestic ordinances were reviewed, we found that the twenty eight cases are applicable after study(82%), the four cases are applicable(12%) and the two cases are not applicable(6%) to Korean system. The result of this study will be source materials for the application of the correct regulations in the field of domestic landscape ordinances providing the theoretical system for the legislation of the landscape ordinances which are characterized as the harmonization between the development and the conservation breaking from the existing uniform and the developmental landscape ordinances.