• Journal of Broadcast Engineering
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• v.14 no.6
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• pp.733-741
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• 2009

The design rule of digital communication systems is the reliable data transmission with high spectral efficiency and minimum allowable power. This paper suggests the method that saves the average power by implementing a multi-dimensional constellation in case of multi-carrier communication system. By using multi-dimensional constellations we can relocate constellation points in the form of a sphere. If we simply convert the two-dimensional QAM modulation into multi-dimensional QAM, constellation points of 2 N dimensional cube form are made up. Relocating outermost constellation points of 2 N dimensional cube form into low energy constellation points, the constellation of the 2 N-dimensional sphere form is made up which decreases power consumption. In this paper, the multi-dimensional constellations of 2 N-dimensional sphere form are designed from 16-QAM to 2,048-QAM, and power reductions are obtained by comparing constellations of 2-dimensional QAMs and multi-dimensional constellations of 2 N-dimensional sphere form. The result shows that the average power consumption of higher dimensional constellations increases, because the more a dimension elevates, the more the relocatable constellation points increase. But, the increment of the average power savings decreases as the a dimension elevates. The transmission of the data by using multi-dimensional constellations of the sphere form is effective to save the average power consumption with little hardware complexity.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2007.11a
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• pp.79-80
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• 2007

• Journal of the Korea Institute of Building Construction
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• v.13 no.6
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• pp.522-529
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• 2013

As concrete forms, panel forms made of plywood used to be widely used, but recently a system form made of aluminum has been broadly adopted because of the advantages it offers in terms of constructability and economy. However, an aluminum form reacts with concrete, which is alkali, and creates hydrogen gas. As a result, air pockets occur on the concrete's surface, and its finishability deteriorates. Therefore, this research analyzed the relationship between the distribution of voids and surface roughness and the damage degree and number of uses of the aluminum form. The analysis of the distribution of voids shows that the number of voids of 0.1~1 mm, which are considered to have occurred because of chemical reaction, was 200~500 on the coating plywood, but was 1 500~2 000 on the aluminum form after 3 uses, and impossible to count after a higher number of uses. Surface roughness was $1.7{\sim}3.2{\mu}m$ on the coating plywood form, but was about $2.6{\mu}m$ after the first use and about $6.8{\mu}m$ after 10 uses, a 2.6-fold increase. Distribution of voids did not show a particular tendency depending upon the degree of damage to the concrete form, but surface roughness showed an increasing tendency as the degree of damage grows. Therefore, when using aluminum forms, surface maintenance should be carried out completely, such as prevention of damages to the form surface coating materials and spreading of separating materials on forms.

• Journal of the Korean Society of Industry Convergence
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• v.25 no.1
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• pp.121-129
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• 2022

With the recent increase in international trade volume the trade volume through ships is also continuously increasing. The treatment of ballast water goes through the following five steps, samples are taken and analyzed at each step, and samples are obtained using a suction pump. These suction pumps have low efficiency and thus need to be improved. In this study, it is to optimize the form of the impeller which affects directly improvements of performance to determine the capacity of suction pump and to fulfill the purpose of this research. To do it, we have carried out parametric design as an input variable, geometric form for the impeller. By conducting the flow analysis for the optimum form, it has confirmed the value of improved results and achieved the purpose to study in this paper. It has selected the necessary parameter for optimizing the form of the pump impeller and analyzed the property using experiment design. And it can reduce the factor of parameter for local optimization from findings to analyze the property of form parameter. To perform MOGA(Multi-Objective Genetic Algorithm) it has generated response surface using parameters for local optimization and conducts the optimization using multi-objective genetic algorithm. with created experiment cases, it has performed the computational fluid dynamics with model applying the optimized impeller form and checked that the capacity of the pump was improved. It could verify the validity concerning the improvement of pump efficiency, via optimization of pump impeller form which is suggested in this study.

• Korean Journal of Construction Engineering and Management
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• v.20 no.4
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• pp.56-68
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• 2019

An optimal selection of form-work is very important in the construction project in terms of construction cost and duration management. Also, it substantially affects the quality of the structure and the finishing work. However, in South Korea, the decision making on the selection of form-work has been based on the experience and intuition of construction practitioners not on the objective data or rational decision-making system. In order to solve the problem, several types of research on the selection of form-work has been processed. However, they did not consider the construction site condition, which is one of the most important factors for the selection of form-work. Thus, the objective of this study is developing the objective decision supporting system considering the site condition. This study provides the quantitative decision support model for optimal form-work based on construction site type. It is expected that the decision support model will help the practitioners decide optimal form-work based on the objective data. It will ameliorate the existing decision making process using experience and intuition. In addition, because the model considers site-conditions, it will provide more accurate and appropriate decision on the selection of an optimal form-work.

• International Journal of High-Rise Buildings
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• v.5 no.1
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• pp.21-30
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• 2016

The structural efficiency of tall buildings heavily depends on the lateral stiffness and resistance capacity. Among those structural systems for tall buildings, outrigger system is one of the most common and efficient systems especially for those with relatively regular floor plan. The use of outriggers in building structures can be traced back from early 50 from the concept of deep beams. With the rise of building height, deep beams become concrete walls or now in a form of at least one story high steel truss type of outriggers. Because of the widened choice in material to be adopted in outriggers, the form and even the objective of using outrigger system is also changing. In the past, outrigger systems is only used to provide additional stiffness to reduce drift and deflection. New applications for outrigger systems now move to provide additional damping to reduce wind load and acceleration, and also could be used as structural fuse to protect the building under a severe earthquake condition. Besides analysis and member design, construction issue of outrigger systems is somehow cannot be separated. Axial shortening effect between core and perimeter structure is unavoidable. This paper presents a state-of-the-art review on the outrigger system in tall buildings including development history and applications of outrigger systems in tall buildings. The concept of outrigger system, optimum topology, and design and construction consideration will also be discussed and presented.

• The Journal of Society for e-Business Studies
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• v.6 no.1
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• pp.1-16
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• 2001

This paper describes a preliminary investigation of contracts with a view towards automating the process of contract match-making. A novel approach based on exploiting Standard Form Contracts(SFC) is described. The approach is shown to be implementable with current technology. A second approach based on Standard Contract Clauses(SCC) which overcomes some of the limitations of Standard Form Contracts, is briefly outlined. The flexibility offered by this approach however, is accompanied by a considerable increase in the complexity of contract match-making. Both Standard Form Contracts and Standard Contract Clauses based match-making point towards an exciting area of future research.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.05a
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• pp.997-1002
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• 2002

Traditional prediction models have been developed with a fixed equation form based on the limited number of data and parameters. If new data is quite different from original data, then the model should update not only its coefficients but also its equation form. However, artificial neural network (ANN) does not need a specific equation form. Instead of that, it needs enough input-output data. Also, it can continuously re-train the new data, so that it can conveniently adapt to new data. Therefore, the purpose of this paper is to develop the I-PreConS (Intelligent system for PREdiction of CONcrete Strength using ANN) that provides in-place strength information of the concrete to facilitate concrete form removal and scheduling for construction.

• 대한상한금궤의학회지
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• v.5 no.1
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• pp.1-17
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• 2013

Objective : The purpose of this study is to help korean medical doctors write case reports based on Shanghanlun six clinical patterns and provisions accurately and effectively. Methods : To achieve the purpose of this study, we reviewed Shanghanlun six clinical patterns and provisions. After this, we formed a case report form according to the importance of Korean medical terms in Shanghanlun. Results : Through this study, we got the consistency and unity of case reports based on Shanghanlun six clinical patterns and provisions. Conclusions : This case report form is designed for gathering clinical data which are organized clearly according to the diagnostic system based on Shanghanlun six clinical patterns and provisions.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2010.05a
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• pp.167-170
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• 2010

In tall building construction, It is important to reduce construction duration of slab form work. Therefore, the purpose of this study is to assess the required performance for reduction of construction duration in slab form work of tall buildings. We surveyed the required performance and their degrees of importance and economical efficiency through the interview and questionnaire survey by related experts. This study proposes the guideline to develop improved formwork system for reduction of construction duration.