• IEMEK Journal of Embedded Systems and Applications
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• v.7 no.5
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• pp.227-239
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• 2012

Recent advances in electronics have enabled various conventional products to incorporate with numerous powerful microcontroller. Generally, an embedded system is a computer system designed for specific control functions within a larger system, often with real-time computing constraints. The growing performance and reliability of hardware components and the possibilities brought by various design method enabled implementing complex functions that improve the comport of the system's occupant as well as their safety. A cyber physical system (CPS) is a system featuring a tight combination of, and coordination between, the system's computational and physical elements. The concept of cyber physical system, including physical elements, cyber elements, and shared networks, has been introduced due to two general reasons: design flexibility and reliability. This paper presents a cyber physical system where system components are connected to a shared network, and control functions are divided into small tasks that are distributed over a number of embedded controllers with limited computing capacity. In order to demonstrate the effectiveness of cyber physical system, an unmanned forklift with autonomous obstacle avoidance ability is implemented and its performance is experimentally evaluated.

• Journal of Information Technology Applications and Management
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• v.13 no.3
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• pp.1-28
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• 2006

In the ubiquitous computing environments. people usually carry multiple information technology devices with them. Personal device network (PDN) refers to the way how people connect multiple IT devices for their personal as well as professional purposes. Even though it has been Quite popular to construct the PDN in ubiquitous computing context, not much research has been conducted on how people actually connected multiple devices and what influences their methods of connection. In this paper we conducted a content analysis on community bulletin boards of IT devices and a contextual inquiry with expert users of PDN for investigating the configurations with which users connect multiple IT devices. Base on the results of two related studies, we identified three major types of PDN configurations, and key factors that influence the configurations of PDN. We conclude this research with guidelines to design a set of devices for each of the three configuration types.

• Journal of information and communication convergence engineering
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• v.7 no.3
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• pp.399-403
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• 2009

In IEEE 802.15.1 (Bluetooth) Ad-hoc networks, the frequency is resolved by the specific part of the digits of the Device clock and the Bluetooth address of the Master device in a given piconet. The piconet performs a fast frequency hopping scheme over 79 carriers of 1-MHz bandwidth. Since there is no coordination between different piconets, packet collisions may occur if two piconets are located near one another. In this paper, we proposed a software/hardware co-design of an adaptive frequency decision mechanism so that more than two different kinds of wireless devices can stay connected without frequency collision. Suggested method was implemented with C program and HDL (Hardware Description Language) and automatically synthesized and laid out. The adaptive frequency hopping circuit was implemented in a prototype and showed its operation at 24MHz correctly.

• Journal of the Korean Society of Clothing and Textiles
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• v.38 no.5
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• pp.611-626
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• 2014

Reading and foreseeing fashion trends is crucial and difficult in the fashion industry due to accelerated and diversified changes in fashion trends. We use network analysis to investigate fashion trends from 2004 to 2013 in order to find the inter-relevance among fashion trends. We extracted words from fashion trend info for women's wear provided by Samsung Design Net, created a 2-mode network of seasons and trend languages, and visualized this network using NodeXl program. Fashion trends repeated a unique pattern during the period. In the first half (2004-2008), retro modern, feminine modern, and ecological modern were dominant trends in consecutive order. The years 2009-2013 witnessed distinctive fashion trends in S/S seasons and in F/W seasons. 11F/W, 12F/W and 13F/W seasons were characterized by artistic creative style. From 2010, natural style dominated S/S seasons. 10S/S and 12S/S seasons were distinguished as a calm natural style that reflected a peaceful and simple life. In 11S/S and 13S/S seasons, soft natural style emerged as a sign of increased importance of inner spirit and natural energy. A seasonal reappearance of trends was observed every two years in S/S seasons that enabled the prediction that 14S/S will see another version of natural style. A macroscopic trend for the last 10 years was represented by the keywords 'modern' and 'natural'. 'Modern' involved the past styles such as 60's, Baroque and the origin of human life. 'Natural' was connected with design elements such as material, silhouette and color. Managerial implications and future study directions are discussed based on the results.

• Journal of Korean Institute of Industrial Engineers
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• v.37 no.1
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• pp.19-29
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• 2011

Cellular network is comprised of several base stations which serve cellular shaped service area and each base station (BS) is connected to the mobile switching center (MSC). In this paper, the configuration modeling and algorithm of a cellular mobile network with the aim of minimizing the overall cost of operation (handover) and network installation cost (cabling cost and installing cost of mobile switching center) are considered. Handover and cabling cost is one of the key considerations in designing cellular telecommunication networks. For real-world applications, this configuration study covers in an integrated framework for two major decisions: locating MSC and assigning BS to MSC. The problem is expressed in an integer programming model and a heuristic algorithm based on Lagrangian relaxation is proposed to resolve the problem. Searching for the optimum solution through exact algorithm to this problem appears to be unrealistic considering the large scale nature and NP-Completeness of the problem. The suggested algorithm computes both the bound for the objective value of the problem and the feasible solution for the problem. A Lagrangian heuristics is developed to find the feasible solution. Numerical tests are performed for the effectiveness and efficiency of the proposed heuristic algorithm. Computational experiments show that the performance of the proposed heuristics is satisfactory in the quality of the generated solution.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.1
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• pp.35-57
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• 2014

Multi-criteria decision making (MCDM) algorithms play an important role in ensuring quality of service in an integrated HetNets (Heterogeneous Networks). The primary objective of this paper is to develop a multi-criteria vertical handoff decision algorithm (VHDA) for best access network selection in an integrated Wireless Local Area Network (WLAN)/Universal Mobile Telecommunications System (UMTS)/Worldwide Interoperability for Microwave Access (WiMAX) system. The proposed design consists of two parts, the first part is the evaluation of an Analytic Hierarchy Process (AHP) to decide the relative weights of handoff decision criteria and the second part computes the final score of the weights to rank network alternatives using Simple Additive Weighting (SAW). SAW ranks the network alternatives in a faster and simpler manner than AHP. The AHP-SAW mathematical model has been designed, evaluated and simulated for streaming video type of traffic. For other traffic type, such as conversational, background and interactive, only simulation results have been discussed and presented in brief. Simulation results reveal that the hierarchical modelling and computing provides optimum solution for access network selection in an integrated environment as obtained results prove to be an acceptable solution to what could be expected in real life scenarios.

• International Journal of High-Rise Buildings
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• v.6 no.3
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• pp.271-277
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• 2017

Safety, livability, and efficiency are the three prominent problems of tall buildings, which are also the severe challenges to designers. We proposed the idea of building the sky town to solve these problems, which can be summarized in two sentences, one is tall building multi-storised, and another one is vertical facilities municipal-infrastructurised. The tall building can be horizontally cut into several multi-storey buildings by some large platforms. The platform extends a certain width to block the fire from spreading. Tall buildings are connected together as a group. One of them is a traffic core, which is used for vertical transportation and MEP. It connects to traffic center such as metro, while most of the other tall buildings' cores can be very much released, so as to achieve maximum efficiency of floor usable area and to give good traffic organization. By combining traffic core, platforms, and multi-storey buildings' inner traffic, a transportation network is formed. Finally, we refer to the design of Raffles City Chongqing to make a sketch of sky town.

• Journal of Korea Society of Digital Industry and Information Management
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• v.8 no.1
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• pp.125-137
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• 2012

As the Internet use explodes recently, the malicious attacks and hacking for a system connected to network occur frequently. For such reason, lots of intrusion detection system has been developed. Intrusion detection system has abilities to detect abnormal behavior and unknown intrusions also it can detect intrusions by using patterns studied from various penetration methods. Various algorithms are studying now such as the statistical method for detecting abnormal behavior, extracting abnormal behavior, and developing patterns that can be expected. Etc. This study using clustering of data mining and association rule analyzes detecting areas based on two models and helps design detection system which detecting abnormal behavior, unknown attack, misuse attack in a large network.

• Journal of Wellbeing Management and Applied Psychology
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• v.6 no.4
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• pp.27-31
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• 2023

Purpose: This study analyzed papers identified by entering the two keywords 'unification education' and 'university' during research from 2013 to 2022 in order to identify trends and key concepts in unification education research at domestic universities. Research design, data, and methodology: The study analyzed 224 papers, excluding those on primary, middle, and high school unification education, as well as unrelated and duplicate papers. The analysis included developing a co-occurrence network of keywords, utilizing topic modeling to categorize research types, and confirming visualizations such as word clouds and sociograms. Results: In the final analysis, the research identified 1,500 keywords, with notable ones like 'Korea,' 'education,' 'unification.' Centrality analysis, measuring influence through connected keywords, revealed that 'Korea,' 'education,' 'north,' and 'unification' held significant positions. Keywords with high centrality compared to their frequency included 'learning,' 'development,' 'training,' 'peace,' and 'language,' in that order. Conclusions: This study investigated trends and structures in university-level unification education by analyzing papers identified with the keywords 'unification education' and 'university.' The use of keyword network analysis aimed to elucidate patterns and structures in university-level unification education. The significance of the study lies in offering foundational data for future research directions in the field of unification education at universities.

• The Transactions of the Korean Institute of Power Electronics
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• v.22 no.4
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• pp.336-344
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• 2017

This paper presents the three-port DC-DC converter modeling and controller design procedure, which is part of the solid-state transformer (SST) to interface medium voltage AC grid to bipolar DC distribution network. Due to the high primary side DC link voltage, the proposed converter employs the three-level neutral point clamped (NPC) topology at the primary side and 2-two level half bridge circuits for each DC distribution network. For the proposed converter particular structure, this paper conducts modeling the three winding transformer and the power transfer between each port. A decoupling method is adopted to simplify the power transfer model. The voltage controller design procedure is presented. In addition, the output current sharing controller is employed for current balancing between the parallel-connected secondary output ports. The proposed circuit and controller performance are verified by experimental results using a 30 kW prototype SST system.