• Journal of Institute of Control, Robotics and Systems
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• v.22 no.2
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• pp.83-88
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• 2016

In this paper, a design method for a logistics transportation robot based on a modular conveyor rack and path planning considering the environment of a logistics center is proposed. The driving part of the logistics transportation robot is designed and the working method of lifter for the transportation function is explained. The design of the modular conveyor rack is also described and an algorithm for a logistics transportation robot using a modular conveyor rack is suggested. The $A^*$ algorithm is improved by using the concept of rotation cost and the initial state of the transportation robot's characteristics. We experimented with a four-step transportation algorithm for a logistics transportation robot using a modular conveyor rack and showed that the proposed method can be used successfully in a logistics center. In addition, we verified the effectiveness of the improved $A^*$ algorithm considering the rotation cost and the initial state of the robot.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.35 no.4
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• pp.16-23
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• 2012

At present, the significance of a new manufacturing system that can shift from 'mass production' and consider life cycles of a product is pointed out and extremely expected. In such a situation, it is recognized that the modular design, often called 'unit design,' is the important design methodology which realizes the new production system enabling 'cost reduction,' 'flexible production of a multi-functional artifact,' 'settlement of an environmental issue,' and so on. A module (unit) of a product is generally defined as 'the parts group made into the sub-system from a certain specific viewpoint.' So far, there have been many researches related to the modular design. However, they are often limited to a certain viewpoint (objective). This paper proposes a simple but effective method for multi-objective modular design. In the proposed method, a new design metric, called similarity index, is proposed to evaluate the modular design candidates from the multiple viewpoints.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.25 no.6
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• pp.471-478
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• 2016

This paper describes a method to design a lightweight modular bridge for a railway infrastructure system. A lightweight design was achieved using the material selection method. Aluminum extrusions and honeycomb sandwich composites were selected as the best materials to reduce the weight of the upper structure of a conventional modular bridge made of carbon-steel material. The structural integrity of the lightweight modular bridge was evaluated under vertical and wind loads. The twisting and bending natural frequencies were also evaluated to investigate its dynamic characteristics. The results showed that the structural integrity and natural frequencies of the lightweight modular bridge, made of aluminum extrusion and sandwich composites, satisfied the design requirements. Moreover, it was found that the weight of the conventional modular bridge made of carbon steel could be reduced by a maximum of 47% using lightweight materials.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.83-84
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• 2023

Wall structure smart modular is a building construction method where modules are manufactured in a factory and assembled on-site. This method is gaining popularity in the construction industry as it reduces construction time and mitigates risks such as material supply and labor costs. Wall structure smart modular is necessary as it provides comfortable temporary classroom space during renovation and remodeling of aging school buildings. The structure and characteristics of each type of temporary classroom modular were compared, and wall structure modular showed superior performance in terms of height and weight competitiveness compared to mixed structures. With these advantages, wall structure modular can ensure economic efficiency and recyclability as a temporary classroom. In the future, we aim to compare and analyze the standards such as inter-floor noise and heat transfer coefficient for wall structure and mixed structures.

• Korean Journal of Construction Engineering and Management
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• v.16 no.6
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• pp.101-111
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• 2015

The modular construction method has been getting more attention followed by global eco-friendly trend as the domestic construction industry has focused more on remodeling and extension work. The modular construction method is an industrialized construction system which is not likely as the existing construction method it manufactures more than 70% modules at the factory then assembling can be completed in a short amount of time on site. The modular construction method has various strengths; shortening of construction period by on-site work decrease, weight pressure reduction by usage of light steel frames and cost saving by repetitive manufacturing. However, it is currently not expanded due to the existing commercialized construction method. Therefore, this research is in order to help the related authorities make decisions to select the construction method and motivate expansion of modular construction method which can be utilized effectively in the extension works. The intention of this research is to stress differentiation from other construction methods in construction period, construction expenses, labor and forces by comparing and analyzing actual cases, to inform competitiveness of modular construction method by concrete effect analysis and to support adoption of the modular construction method into the domestic industry.

• Korean Journal of Construction Engineering and Management
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• v.19 no.6
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• pp.124-134
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• 2018

Despite the many advantages of modular housing, low preference for modular housing for consumers who are familiar with RC structure leads to high construction cost of modular housing. The cost of modular buildings is about 130% of that of RC structures, so it is urgent to secure economical efficiency of modular buildings. Therefore, in this study, after calculating the savings amount of modular housing by type of construction work, economic analysis was conducted from a long - term perspective. In order to carry out the research, the authors compiled and analyzed the material cost, labor cost, and expenses incurred by each type of work by reclassifying the statement of the modular housing into the factory production and the site installation. After that, Pareto diagrams were created to find a core work that is included in the cost ratio of about 80%, and selected it as a cost reduction subject. Based on the assumption that the market size of domestic modular housing is similar to the level of modular advanced countries such as Japan and European countries, six cost reduction methods were set up that reflects the characteristics of the modular construction method and used for the expert interviews. Cost saving potentials in percentage from the interview were converted to the amount of savings that can be achieved by each type of method when applying the method. Finally, the findings of the study are expected to suggest long-term directions for technical development for modular construction and cost savings.

• International conference on construction engineering and project management
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• 2020.12a
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• pp.75-84
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• 2020

Modular construction is a construction method whereby prefabricated volumetric units are produced in a factory and are installed on site to form a building block. The construction productivity can be substantially improved by the manufacturing and assembly of standardized modular units. 3D printing is a computer-controlled fabrication method first adopted in the manufacturing industry and was utilized for the automated construction of small-scale houses in recent years. Implementing 3D printing in the fabrication of modular units brings huge benefits to modular construction, including increased customization, lower material waste, and reduced labor work. Such implementation also benefits the large-scale and wider adoption of 3D printing in engineering practice. However, a critical issue for 3D printed modules is the loading capacity, particularly in response to horizontal forces like wind load, which requires a deeper understanding of the building structure behavior and the design of load-bearing modules. Therefore, this paper presents the state-of-the-art literature concerning recent achievement in 3D printing for buildings, followed by discussion on the opportunities and challenges for examining 3D printing in modular construction. Promising 3D printing techniques are critically reviewed and discussed with regard to their advantages and limitations in construction. The appropriate structural form needs to be determined at the design stage, taking into consideration the overall building structural behavior, site environmental conditions (e.g., wind), and load-carrying capacity of the 3D printed modules. Detailed finite element modelling of the entire modular buildings needs to be conducted to verify the structural performance, considering the code-stipulated lateral drift, strength criteria, and other design requirements. Moreover, integration of building information modelling (BIM) method is beneficial for generating the material and geometric details of the 3D printed modules, which can then be utilized for the fabrication.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10a
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• pp.243-246
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• 1996

Modular robot manipulator is a robotic system assembled from discrete joints and links into one of many possible manipulator configurations. This paper describes the design method of newly developed modular robot manipulator and the methodology of a task based reconfiguration of it. New locking mechanism is proposed and it provides quick coupling and decoupling. A parallel connection method is devised and it makes modular robot manipulator working well and the number of components on each module reduced. To automatically determine a sufficient or optimal arrangement of the modules for a given task, we also devise an algorithm that automatically generates forward and inverse manipulator kinematics, and we propose an algorithm which maps task specifications to the optimized manipulator configurations. Efficient genetic algorithms are generated and used to search for a optimal manipulator from task specifications. A few of design examples are shown.

• Journal of the Korean Institute of Intelligent Systems
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• v.13 no.4
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• pp.409-415
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• 2003

Recently, the modular learning are very popular and receive much attention for pattern classification. The modular learning method based on the "divide and conquer" strategy can not only solve the complex problems, but also reach a better result than a single classifier′s on the learning quality and speed. In the neural network area, some researches that take the modular learning approach also have been made to improve classification performance. In this paper, we propose a simple modular neural network for characters recognition of vehicle number plate and evaluate its performance on the clustering methods of feature vectors used in constructing subnetworks. We implement two clustering method, one is grouping similar feature vectors by K-means clustering algorithm, the other grouping unsimilar feature vectors by our proposed algorithm. The experiment result shows that our algorithm achieves much better performance.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.12 no.1
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• pp.136-142
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• 2001

In this paper, a method of canceling and suppressing differential mode crosstalk noise signals caused by non-uniform coupling between two transmission lines in UTP (unshielded twisted pair) modular jacks is discussed. Differential mode crosstalk noise signals in balanced transmission lines with UTP modular jacks were suppressed, by applying field cancellation techniques to this modular jack. To verify an effectiveness of the field cancellation techniques, 8 pin modular jacks were made, and the NEXT (Near End Crosstalk) losses were measured to prove its applicability by the network analyzer(HP8720C) at 100 Mb/s.