• Journal of the Korean Institute of Intelligent Systems
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• v.6 no.4
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• pp.71-80
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• 1996

This paper presents stabilization and position control of the Inverted-Pendulum system with cart by using Evolution Strategies that is one of the Evolutionary Computation and is effective in searching real number. The control input of the Inverted-Pendulum is the element of chromosome corresponding to the divided space of Inverted-Pendulum state variable x, x, 0, 0 . In general, the larger the length of the chromosome is, the longer the time of evolution to search optimal solution is. So in this paper, we propose a scheme that reduce the state space by half by taking the method, that is, converting only the sign of the control input without obtaining separately for the symmetrical sections of the Inverted-Pendulum to improve the speed of Evolution, and improved the efficiency of the entire system in addition to the improvement of the chromosome's evolution time by carrying out the chromosome's evolutional process by two steps one of which is that cart is positioned near the control point and the other cart is positioned far from that point. We propose another method that is Neural Network-Evolution StrategiedNN-ES) Controller. We verify the effectiveness of the proposed control scheme by computer simulations.

• Imaging Science in Dentistry
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• v.33 no.1
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• pp.5-14
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• 2003

Purpose: To observe the histologic pattern of healing in molar tooth extraction sockets of streptozotocin-induced diabetic rats following irradiation. Materials and Methods: Mature Sprague-Dawley rats were divided into three groups: control, diabetic, and diabetic-irradiated groups. Diabetes mellitus was induced by injecting streptozotocin. Control rats were injected with a citrate buffer only. After 5 days, the right maxillary first molar was extracted under general anesthesia from each of the rats. After the extraction, rats in the diabetic-irradiated group were irradiated with a single absorbed dose of 10 Gy to the head and neck region. The rats were killed at 1, 3, 7, 14, 21, and 28 days after treatment. Tissue sections were stained with hematoxylin-eosin and Masson's trichrome. Results: In the diabetic and diabetic-irradiated groups, the early healing process of the socket extraction was similar to the control group, but bone formation was delayed at 7 days after the treatment. In the diabetic-irradiated group, alveolar bone surrounding the extraction socket showed signs of necrosis at 3 days after treatment, and hemorrhage was observed in connective tissue within the extraction socket at 14 days after treatment. Conclusion: This experiment revealed that the healing process of the extraction socket was severely delayed and retarded by irradiation in the diabetic state.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.44 no.4
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• pp.182-190
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• 2018

Objectives: Head and neck squamous cell carcinoma (HNSCC) is the sixth most common malignancy worldwide. Inconsistency in various histopathologic features for predicting nodal metastasis and overall prognosis and a better understanding of molecular mechanisms of tumourigenesis have shifted the focus to a search for more definitive predictive markers. To identify the role of two immunohistochemical (IHC) markers, E-cadherin and cyclin D1, as predictive markers of aggressiveness in HNSCC and to assess clonal expansion of tumour cells. Materials and Methods: A total of 66 cases of HNSCC with neck node dissection were studied. IHC was performed on primary tumour sections and lymph nodes showing metastatic deposits. Histopathological parameters such as tumour grade and TNM stage together with nodal status were compared according to expression of the two markers. Fischer's chi-square test was used to assess the correlation between the two markers and histopathological parameters. Results: Out of 66 cases studied, 37 showed LN metastasis. Most of the patients were male, and the most common tumour site was buccal mucosa. We found a significant association between loss of E-cadherin and node metastasis (P<0.001) and higher TNM stage (P<0.001). Cyclin D1 overexpression was significantly associated with only nodal metastasis (P=0.007). No significant association with tumour grade was found for either marker. The subgroup of E-cadherin loss with cyclin D1 overexpression was associated with the maximum incidence of nodal metastasis and higher TNM stage, highlighting the importance of using a combination of these two markers. A significant association was noted between the expression of markers at the primary site and at nodal deposits, indicating clonal expansion. Conclusion: A combination of the two markers E-cadherin and cyclin D1 can predict prognosis in HNSCC, although tumour heterogeneity may affect this association in some cases.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.12 no.1
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• pp.105-113
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• 1982

Because of the development of rampant caries, osteomyelitis and osteoradionecrosis that occur after radiation therapy of oral cancers, extraction of teeth at or near the malignant lesion has been done in the past. Few, however, have studied the radiation effect on the healing of extraction wounds. This study is concerned with the effect of Co-60 irradiation on the healing process of extraction wounds in rats. Fifty six, male, Spraque-Dawley rats are used. The right first molar of the mandible is extracted from all animals. They are divided into three experimental groups of 14 each and a control group of 14. Three experimental groups are irradiated respectively with 200 rad, 400 rad and 600 rad and a pair of rats in each group are killed on days 1, 3, 5, 7, 14, 21 and 28 after irradiation. Two animals from the control group are killed on the day when the experimental rats are killed. The irradiated hemimandibles are fixed in 10% neutral formalin, decalcified in 5% trichloroacetic acid, embedded in paraffin and sectioned. The sections are stained in hematoxylin and eosin, van Gieson, Masson's trichrome or silver nitrate. Results show that in general radiation effects on healing extraction wounds are dose dependent; i.e., the higher is the dose, the greater is the histologic changes observed: 1. Irradiation tends to retard blood clot organization and epithelial regeneration. 2. An increase in the number of giant cells and osteoclasts is noted after irradiation. 3. Formation of regenerating connective tissues around and within the extraction site is com- promised, and a clear reduction of primitive mesenchymal type connective cells is noted. 4. The healing process begins along the lateral aspect of the extraction socket in the control, while irregular histologic appearances of the brabecular pattern is present in the experimental rats.

• Journal of Agricultural Extension & Community Development
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• v.18 no.4
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• pp.825-860
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• 2011

For the first time basic settlement area development plan was established in 2010, in order to promote cooperative coexisting development among regions, as time that regional competitiveness determines national competitiveness started. Basic settlement area development plan is composed of 7 sectors and 24 general subsidy projects. It was judged that experience and tourism business as the center is required to be analyzed, which may have effect on activation of farm village, fishing village and mountain village, and inflow of city people, in agriculture, forestry and fishery sector in order that added value of agriculture and fishery is increased, and tangible and intangible resources are applied, and pure agriculture, forestry and fishery is developed. And currently farm village, mountain village and fishing village of our country faces desperate crisis situation that they cannot help groping for substitutive to create new revenue model, and agriculture and fishery of primary industry has limit of increasing income of farmer and fisherman. Agriculture, forestry and fishery experience and tourism business was classified by types, and then standard of 12 categories and 48 sections was prepared, for searching method to supplement and develop it. Trend of experience and tourism business was understood, and problem was found, and then it may be used as indicator material to carry out creative and differentiated business plan establishment and business operation, and may be opportunity to reject overlapped business among regions, and to promote balanced regional development.

• The Journal of Korean Association of Computer Education
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• v.12 no.2
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• pp.23-31
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• 2009

The new national K-12 Information subject curriculum which will be effective in year 2010 includes algorithm and programming sections. Programming languages in K-12 are more effective the Educational Programming Language (EPL) than general language, because it focuses on developing problem solving ability rather than training a programmer. Therefore, it is necessary to study for suitable EPL in Korean K-12 curriculum. In this study, we studied and analyzed various types of EPLs available and strategies to apply them to the new national curriculum. First of all, we chose 26 educational programming languages and analyzed their characteristics and functions. Also, we investigated associations between key factors of the new Information curriculum and each language and suggested a proper language for their students' level. Finally, we considered possible problems and suitability to Korean K-12 students. The result of this study help us to choose what is the proper EPL and to consider applicability and criteria of EPLs.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.21 no.1
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• pp.113-124
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• 2008

Distributed operation of overall structural design process, by which product optimization and process parallelization are simultaneously implemented, is presented in this paper. The database-interacted hybrid method, which selectively takes the accustomed procedure of the conventional method in the framework of the optimal design, is utilized here. The staged application of design constraints reduces the computational burden for large complex optimization problems. Two kinds of numeric and graphic processes are simultaneously implemented by concurrent engineering approach in the distributed environment of PC networks. The former is based on finite element optimization method and the latter is represented by AutoCAD using AutoLISP programming language. Numerical computation and database interaction on servers and graphic works on independent clients are communicated through message passing. The numerical experiments for some steel truss models show the validity and usability of the method. This study has sufficient adaptability and expandability, in that it is based on general methodologies and industry standard platforms.

• Journal of Biomedical Engineering Research
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• v.15 no.3
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• pp.237-244
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• 1994

We investigated the qualitive and quantitative properties in EEG signal which responds to auditory stimulus with increaing the sound-cutting frequency from 2 Hz to 20 Hz by 2 Hz step units, by chaotic dynamics. To bigin with, general chaotic properties such as fractal mechanism, 1 If frequency spectrum and positive Lyapunov exponent are discussed in EEG signal. For evoked potential with given auditory stimulus, the route to chaos by bifurcation diagram and the changes in geometrical property of Poincare sections of 2-dimensional psedophase space is observed. For that containing spontaneous potential, seen as the random background signal, the chaotic attractors in 3-dimensional phase space are found containing the same infomation as the above mentioned evoked potential. Finally the chinges of Lyapunov exponent by various sound-cutting frequencies of stimulus and by the various spatial positions (occipital region) in a brain surface to be measured, are illustrated meaningfully.

• The Journal of Korea Robotics Society
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• v.1 no.1
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• pp.17-24
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• 2006

Though the final goal of mobile robot navigation is to be autonomous, operators' intelligent and skillful decisions are necessary when there are many scattered obstacles. There are several limitations even in the camera-based tele-operation of a mobile robot, which is very popular for the mobile robot navigation. For examples, shadowed and curved areas cannot be viewed using a narrow view-angle camera, especially in bad weather such as on snowy or rainy days. Therefore, it is necessary to have other sensory information for reliable tele-operations. In this paper, sixteen ultrasonic sensors are attached around a mobile robot in a ring pattern to measure the distances to obstacles. A collision vector is introduced in this paper as a new tool for obstacle avoidance, which is defined as a normal vector from an obstacle to the mobile robot. Based on this collision vector, a virtual reflection force is generated to avoid the obstacles and then the reflection force is transferred to an operator who is holding a joystick to control the mobile robot. Relying on the reflection force, the operator can control the mobile robot more smoothly and safely. For this bi-directional tele-operation, a master joystick system using a hall sensor was designed to resolve the existence of nonlinear sections, which are usual for a general joystick with two motors and potentiometers. Finally, the efficiency of a force reflection joystick is verified through the comparison of two vision-based tele-operation experiments, with and without force reflection.

• The Journal of Engineering Geology
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• v.11 no.2
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• pp.153-161
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• 2001

The quantitative evaluation of the stereo graphic projection, the limit equilibrium analysis, the finite difference analysis, the distinct element methocI is a analytical evaluation using many variables. Through the reliability analysis by the point estimation technique, uncertainty of other variables that have an effect on the stability of the rock slo~ was considered. The organized evaluation method of the approximate reasoning concept and using a fuzzy language was developed to confer and analysis the failure factors in planning and constructing the rock slope. Considering the result of the an- alysis, it was demonstrated that stability of entire sections can be evaluated through reliability analysis of point estimation technique. The results of stability evaluation by Fuzzy Approximate Reasoning is generally identical with the results of other existirw; analyses. As mentioned above, general and organized evaluation of special qualities of rock slope is possible using RMR Classification, Stereo Graphic Projection, Limit Equilibriwn Analysis, Finite Difference Analysis, Distinct Element Method, Point Estimation Technique, and Fuzzy Approximate Reasoning.