• Steel and Composite Structures
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• v.23 no.2
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• pp.161-172
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• 2017

A new composite tube connection method called the pre-tightened teeth connection technique is proposed to improve the composite tube connection efficiency. This paper first introduces the manufacturing process of the proposed technique. It then outlines how the mechanical properties of this technology were tested using four test groups. The factors that influence the load-bearing capacity and damage model of the connection were analyzed, and finally, the transfer load mechanism was investigated. The following conclusions can be obtained from the research results. (1) The new technique improves the compressive connection efficiency by a maximum of 79%, with the efficiency exceeding that of adhesive connections of the same thickness. (2) Changing the depth of teeth results in two types of damage: local compressive damage and shear damage. The bearing capacity can be improved by increasing the depth, length, and number of teeth as well as the pre-tightening force. (3) The capacity of the technique to transfer high loads is a result of both the relatively high interlaminar shear strength of the pultruded composite and the interlaminar shear strength increase provided by the pre-tightening force. The proposed technique shows favorable mechanical properties, and therefore, it can be extensively applied in the engineering field.

• Journal of Korea Multimedia Society
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• v.17 no.12
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• pp.1484-1493
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• 2014

Recently, Industry 4.0 (next generation industrial revolution) designed by Germany to retain initiative in manufacturing business is actively studied. Goal of Industry 4.0 is 'Smart factory' which manages progress of production, supply logistics and services. To achieve the goal, we can construct value creation and new business model by integrating organically with production management systems which is existing and cyber-physical systems, Internet of Things, Services Internet and sensor, etc. However, if integration with production management systems does not work effectively by adding and developing new technologies, It does not have performance. Hence, in this research, we will analysis Industry 4.0 which is possible for small quantity batch production and one of the light and flexible manufacturing systems, and based on this, we will suggest methodology to horizontally integrate with production management systems.

• International Commerce and Information Review
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• v.10 no.1
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• pp.3-31
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• 2008

Northeast Asia is expected to be on economic bloc which is competed with other economic blocs such as EU, NAFTA. E-Commerce based on IT and networking results in paradigm shift in Northeast Asian Nations, that is, Korea, China, Japan, Taiwan etc. There are the similarities and differences in e-Commerce situations in these nations. The differences are the gaps in e-Commerce infrastructures such as Internet, e-Commerce solution, e-payment system and e-logistics system etc. A number of interorganizational, intraorganizational and usage level factors influences the performances of all firms using e-Commerce tools. As result of this empirical study, China records low level of e-Commerce in terms of environmental aspects, usage and performance while Korea and Japan record relatively high levels. It is also found that non-economic performance is higher than economic performance in Northeast Asian firms. The purpose of this paper contributes to resolve the digital divide in Northeast Asia and to improve e-Commerce infrastructures in Northeast Asia by estimating current e-Commerce levels of Northeast Asian countries and suggesting future development strategies of those countries through e-Commerce cooperation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.10a
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• pp.879-886
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• 2007

EPC (Electronic Product Code) tags and RFID (Radio Frequency IDentification) technology are said to have potential to change the ways individuals, organizations and societies operate on the everyday basis. In the near future, it is expected that every major retailer will use RFID and EPC systems to track the movement of products from suppliers to warehouses, store backrooms and eventually to points of sale. Recent efforts in EPC tags and RFID technology attempt to achieve an appropriate kind of interaction between technical and business areas. In this paper, we explore the fundamental characteristics of RFID and EPC applications and then review the different research studies of RFID technology and EPC system that have been proposed new theories and concepts that have emerged and utilized in different business fields of manufacturing and logistics. It provides an overview of the study achievements within the domain and critically evaluates the various approaches through the use of a case study and the construction of its comparison framework. The different research studies indicated that RFID and EPC systems will become more pervasive in the future and the changes that occur over the next few years will make for a further fascinating research area.

• Journal of the Society of Naval Architects of Korea
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• v.41 no.5
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• pp.55-62
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• 2004

The logistics of entire shipbuilding process are integrated during the block erection process and the schedules for the erection process are made prior to. the schedules of any other processes. Therefore, efficient scheduling of the block erection process are one of most important issues in shipbuilding. There are only a few studies published regarding block erection scheduling methods because of its complexity and variability. This paper proposes an algorithm for diminution of maximum load based on constraint satisfaction technique. it is developed primarily for the efficiency in load leveling and applicability to the actual block erection process. The proposed algorithm is applied to actual block erection process and the results shows improvements in load leveling. It can also be used for the scheduling of fabrication, sub-assembly, and assembly to improve load leveling.

• International Journal of Highway Engineering
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• v.19 no.6
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• pp.75-81
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• 2017

PURPOSES : So far, aged cement concrete pavement on express highways has been rehabilitated mainly with asphalt concrete inlay. However, potholes were the major problem, and they shortened the life of the inlay mainly owing to the poor drainage of water once it infiltrated the interface of the concrete and asphalt. The purpose of this study is to compare the performance and economic efficiency of asphalt overlay and inlay. METHODS : Overlay and inlay were compared through accelerated pavement testing, and a life-cycle cost analysis was conducted in this study using the CA4PRS program. RESULTS and CONCLUSIONS : It was found from accelerated pavement testing that the overlay exhibited reflective crack resistance that was more than twice as effective as that of inlay. The total cost (construction cost + user cost) within the analysis period (20 years) of the overlay was 37% lower than that of the inlay.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.1765-1768
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• 2009

Honam area is one of the under-industrial areas in Korea and because of this it has low weight in the total container transportation in Korea. Also the railway distance from honam area to the main container ports like Busan port and Gwangyang port is so short that the portion of rail container transportation occupies about 10 percent in total container transportation amount in Honam area. But on the contrary of those situations, 1st step Jangsung inland container depot (ICD) was finished as one of the main logistics facilities in Korea and 2nd Jangsung inland container depot is under construction. To promote rail container transportation in Honam area which has shortage of container transportation demand, it is necessary to give adequate transport service to the client. So, this research studied some methods for promoting rail container transportation in Honam area. The subject of survey is freight agent and survey items are selected to find the present situation of rail container transportation in Honam area. And from the survey results various strategies will be suggested to promote rail container transportation in Honam area.

• Journal of the Korea Society of Computer and Information
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• v.5 no.4
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• pp.200-210
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• 2000

Distribution Activity for customer is preferred at Physical distribution system in e-commerce, so fast delivery and low distribution cost determine the core competency of enterprise. Because there is no cooperative system between with distribution centers in traditional distribution system, it is difficult to optimize the system. The purpose of this paper is to propose a cost structure model for multi-stage distribution system, which is used for determination of joint lot size and optimal demand and transportation policy. It is expected to contribute to development of algorithm for joint distribution system, which is minimized the transportation cost by the result of this cost structure model.

• Journal of the Korea Society of Computer and Information
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• v.23 no.5
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• pp.9-14
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• 2018

For an efficient management of electricity market and power systems, accurate forecasts for electricity demand are essential. Since there are many factors, either known or unknown, determining the realized loads, it is difficult to forecast the demands with the past time series only. In this paper we perform a cluster analysis on electricity demand data collected from Jan. 2000 to Dec. 2017. Our purpose of clustering on electricity demand data is that each cluster is expected to consist of data whose latent variables are same or similar values. Then, if properly clustered, it is possible to develop an accurate forecasting model for each cluster separately. To validate the feasibility of this approach for building better forecasting models, we clustered data with t-SNE. To apply t-SNE to time series data effectively, we adopt the dynamic time warping as a similarity measure. From the result of experiments, we found that several clusters are well observed and each cluster can be interpreted as a mix of well-known factors such as trends, seasonality and holiday effects and other unknown factors. These findings can motivate the approaches which build forecasting models with respect to each cluster independently.

• Journal of Korea Society of Digital Industry and Information Management
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• v.10 no.1
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• pp.181-193
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• 2014

The environment of supply chains is rapidly changed to global and eco-freindly work process. However, at current environment, it is not easy to grasp work flow and to analyze energy efficiency. Improving energy efficiency and visibility for goods flow can contribute to increases in customer attitudes and reductions in overall production costs Additionally, it can lead to increases in work efficiency and reductions in overall production costs. Until recently, efforts to improve energy performance focused on manufacturing industry. Those efforts have expanded to the supply chain. In this paper, we perform business process modeling about supply chain for visibility and sustainability - information and component flows - from assembly plants to logistics. This paper defines the work and information flows by modeling the underlying logical structures of the supply chain and the business processes that determine impact of visibility and sustainability. We model processes using the modeling methodology specified by UN/CEFACT. This methodology explains business process functionality and business transactions by UML diagram. The output of this paper would be useful in grasping work flow and capturing the used energy.