• Korean Journal of Construction Engineering and Management
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• v.10 no.6
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• pp.88-98
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• 2009

Construction industries have increasingly utilized Building information Modeling (BIM) technologies. Interoperability - the capability for BIM data to run from one computer application to another in the life cycle of a project has become one of the principal research areas. Enhancing interoperability inevitably requires information structures that are standardized throughout the construction industries. As a candidate of the data exchange standard, Industry Foundation Classes (IFC) has been developed and several researches recently performed to measure its richness of digital data exchange. But doubts have been brought up whether IFC meets a sufficient level of interoperability since the research result revealed a number of cases of information misrepresentation and loss. This research presents the lessons learned from the interoperability tests of three widely used 3D design applications including Graphisoft's Archicad, Autodesk's Revit, and Bentley's Bentley Architecture. One building's architectural and structural design data were modeled with the three tools and exchanged through IFC respectively for interoperability test.

• KIEAE Journal
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• v.11 no.2
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• pp.75-82
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• 2011

In Korea, the ratio of population in urban areas used to be only 50.1% in 1970, but with the value risen to 90.8% in 2009, urbanization is going on rapidly. Urbanization, which occurs by the rampantly planted buildings, has become major source of raising building density, changing wind direction and reducing wind amount, and such reductions are affecting even inside the building. In each year, among the total energy consumption in Korea, residential portion takes up significant ratio, and specifically the ratio of apartment house is shown to be highest. In order to solve such problem, many studies are being conducted for the improvement of natural ventilation performance. The natural ventilation performance of apartment house are significantly determined by the characteristics of external and internal structure, but in macroscopic perspective, the performance is established fundamentally by the layout characteristics of the main building of the apartment house in preparation for wind conditions. So far researches on raising the thermal comfort through elevation of ventilation performance have been conducted actively, but many of them propose only theoretical concepts deduced through wind path analysis, and do not include any indicator to measure ventilation performance simply only with area data from layout planning stage. Therefore, in this study, gap ratio a wind field measuring indicator was developed, and after the ventilation characteristics by layout types and main building uniformity were identified, the scope of gap ratio efficient for ventilation and that of uniformity were clarified, followed by verification through simulation.

• Journal of the Economic Geographical Society of Korea
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• v.12 no.4
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• pp.344-363
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• 2009

The number of International college students has dramatically increased in Korea since 2000 as the government has made a consistent effort to draw in international students to strengthen the competitiveness of higher education and to improve the international balance of payments. An increase of incoming international students help Korean universities solve a current problem of decreasing student numbers and bring financial benefits. However, not much is known about their intentions and decision-making process. This study tries to investigate their immigration process and backgrounds that have not yet been dealt with seriously in academic areas. The immigration process can be divided into 3 steps - pre-immigration, settlement and adaptation, post-immigration. Characteristic of each step related to a main decision-making are investigated in the paper. Their decision for studying in Korea depends on various factors and conditions. Especially, economical, personal, and vocational factors or motives in combination influence their decision-making at each step.

• The Journal of Korean Academy of Prosthodontics
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• v.44 no.1
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• pp.85-102
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• 2006

Statement of problem: Currently, there are some 20 different geometric variations in implant/abutment interface available. The geometry is important because it is one of the primary determinants of joint strength, joint stability, locational and rotational stability. Purpose: As the effects of the various implant-abutment connections and the prosthesis height variation on stress distribution are not yet examined this study is to focus on the different types of implant-abutment connection and the prosthesis height using three dimensional finite element analysis. Material and method. The models were constructed with ITI, 3i TG, Bicon, Frialit-2 fixtures and solid abutment, TG post, Bicon post, EstheticBase abutment respectively. And the super structures were constructed as mandibular second premolar shapes with 8.5 mm, 11 mm, 13.5 mm of crown height. In each model, 244 N of vertical load and 244 N of $30^{\circ}$ oblique load were placed on the central pit of an occlusal surface. von Mises stresses were recorded and compared in the crowns, abutments, fixtures. Results: 1. Under the oblique loading, von Mises stresses were larger in the crown, abutment, fixture compared to the vertical loading condition. 2. The stresses were increased proportionally to the crown height under oblique loading but showed little differences with three different crown heights under vertical loading. 3. In the crown, the highest stress areas were loading points under vertical loading, and the finish lines under oblique loading. 4. Under the oblique loading, the higher stresses were located in the fixture/abutment interface of the Bicon and Frialit-2 systems compared to the ITI and TG systems. Conclusions: The stress distribution patterns of each implant-abutment system had difference among them and adequate crown height/implant ratio was important to reduce the stresses around the implants.

• The Journal of Korean Academy of Prosthodontics
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• v.44 no.1
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• pp.10-19
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• 2006

Statement of problem : The various kinds of properties of post and core may affect the stress distribution to the root of endodontically treated teeth Purpose: To evaluate the influence of various kinds of properties of post and core to the stress distribution to the root of endodontically treated teeth. Material and methods: Mandibular first premolar, prepared by general shape of post and core with gold crown, was used to two dimensional axisymmetric modeling for finite element analysis. Then property values of 8 different kinds of post and core was substituted for each. Finally, stress distribution shown areas around the root of post and core was analysed after applying 50N of vortical and oblique load. Results: 1. Stress value of oblique load was much higher than the maximum stress value of vertical load. 2. Under oblique load, very concentrated stress was located on post periapical area and variations in stress were very severe. Contrary to this, stress distribution was relatively uniform in vertical load. 3. Post materials with higher elastic modulus showed relatively more apically focused stress, and post materials with lower elastic modulus showed stress focused on cervical area on the axial wall of post. 4. Stress change according to the properties of core was shown only in the cervical area of post and below core as the higher elastic modulus, then increased in stress. 5. Post and core with medium value of elastic modulus showed relatively uniform stress distribution. Conclusions: Post materials with higher elastic modulus showed relatively more apically focused stress, and post materials with lower elastic modulus showed stress focused on cervical area on the axial wall of post. Stress change according to the properties of core was shown only in the cervical area of post and below core.

• Journal of the Korean Institute of Landscape Architecture International Edition
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• no.1
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• pp.111-119
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• 2001

This study aims both to analyze view resources of on agricultural village and its original view image in order to establish indexation and the direction of development and to present assessment model of agricultural view for expectations in plan change for and improvement of agricultural view and alternative valuation. To do this, I selected four agricultural villages as the case areas for this study and examined view resources and their residents' consciousness through a questionnaire and investigated the image preference degree of agricultural village view and view preference. The results of this study are as follows: 1. The newly-introduced artificial view elements, according to development, are a hindrance element of agricultural view; as such Commercial buildings and transmission towers show the highest frequency and are increasing. The problem is that development is being made without any systematic plan. 2. In the examination of images of agricultural villages, the traditional ones are 2.82 on average, which means the view is modern; the natural ones are 3.3 on average, which indicates natural images; the agricultural ones are 3.67 on average, which emerge as agricultural images. View preference degree is 3.34 on average, which is usually good. 3. It is proved that all of the variables of type of location form and view image increase the degree of view preference; size in causal relation can be identified by parameter estimate; that Type I. image variables of agricultural-ness contribute to the dependent variables, view preference degree. 4. It is identified that view preference degree according to location from emerges mountain type, champaign type, and suburbs type in order of preference.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.5
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• pp.1093-1102
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• 2010

Principal component analysis (PCA) is a well-known method for dimension reduction while maintaining most of the variation in data. Although PCA has been applied to many areas successfully, it is sensitive to outliers. Several variants of PCA have been proposed to resolve the problem and, among the variants, robust fuzzy PCA (RF-PCA) demonstrated promising results. RF-PCA uses fuzzy memberships to reduce the noise sensitivity. However, there are also problems in RF-PCA and the convergence property is one of them. RF-PCA uses two different objective functions to update memberships and principal components, which is the main reason of the lack of convergence property. The difference between two functions also slows the convergence and deteriorates the solutions of RF-PCA. In this paper, a variant of RF-PCA, called RF-PCA2, is proposed. RF-PCA2 uses an integrated objective function both for memberships and principal components. By using alternating optimization, RF-PCA2 is guaranteed to converge on a local optimum. Furthermore, RF-PCA2 converges faster than RF-PCA and the solutions found are more similar to the desired solutions than those of RF-PCA. Experimental results also support this.

• Journal of KIISE:Software and Applications
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• v.33 no.7
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• pp.624-635
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• 2006

This paper applies simulated annealing algorithm to the problem of generating a plan for intra-block remarshalling with multiple transfer cranes. Intra-block remarshalling refers to the task of rearranging containers scattered around within a block into certain designated target areas of the block so that they can be efficiently loaded onto a ship. In generating a remarshalling plan, the predetermined container loading sequence should be considered carefully to avoid re-handlings that may delay the loading operations. In addition, the required time for the remarshalling operation itself should be minimized. A candidate solution in our search space specifies target locations of the containers to be rearranged. A candidate solution is evaluated by deriving a container moving plan and estimating the time needed to execute the plan using two cranes with minimum interference. Simulation experiments have shown that our method can generate efficient remarshalling plans in various situations.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.10
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• pp.1270-1275
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• 2016

Recently, the entertainment programs with vocal skills assessment through the broadcasting and cable broadcasting have become very popular. But, in spite of higher popularity, present performance evaluation methods including musical sympathy of the pop singers and plain performers in broadcastings are absolutely dependent on the subjective feelings of audience assessors who evaluate the musical sympathy in these programs. For solving this problem, quantitative methods instead of subjective methods in the entertainment industries for evaluating pop singer's performance and musical sympathy are taken as important issues and social demands. For this, in this paper, we propose a visual and quantitative evaluation method by applying ICT technologies that can be evaluated in all areas of musical sympathy as well as a singer's assessment.

• The KIPS Transactions:PartA
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• v.12A no.6 s.96
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• pp.547-556
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• 2005

Online collaborative teaming, which has emerged as a new type of education in knowledge-based society, is being discussed actively in the areas of action learning at companies and project-based learning and inquiry-based learning at schools. It regards as an effective method for improving learners practical and highly advanced problem solving abilities, and for stimulating their absorption into learning through pursuing common goals of learning together. Different from individual learning, however, collaborative learning involves complicated processes such as organizing teams, setting common goals, performing tasks and evaluating the outcome of team activities .Thus, it is difficult for a teacher to promote and evaluate the whole process of collaborative learning, and it is necessary to develop systems to support collaborative learning. Therefore, in order to monitor and promote interaction among learners in the process of collaborative learning, the present study developed an extensible collaborative teaming supporting agent (ECOLA) in online learning environments.