• Journal of the Institute of Electronics Engineers of Korea TC
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• v.42 no.12
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• pp.37-44
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• 2005

This paper proposes a hybrid scheme for dynamic bandwidth allocation(DBA) in Ethernet passive optical network(EPON), which combines advantages of adaptive cycle and constant cycle-based schemes. The proposed scheme is based on IPACT scheme, but it operates as adaptive cycle or constant cycle mode according to the queue status of optical line terminal(OLT) for downstream transmission. Simulation results showed that the proposed scheme could achieve a similar throughput in downstream transmission to a constant cycle-based DBA scheme, while producing a similar delay performance to the IPACT scheme in upstream transmission.

• Journal of Digital Convergence
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• v.14 no.7
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• pp.21-27
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• 2016

Big Data is gathering all the attention from every business community. Pervasive use of machine-to-machine (M2M) applications and mobile devices bring an explosion of data. By analyzing this data, the private and public sectors can benefit in the areas of cost reduction and productivity. The Korean government is actively pursuing Big Data initiatives to promote its usage. This paper aims to select industries which fit for the development of Big Data with a verification of the experts. The analytic hierarchy process (AHP) is applied to systematically derive the opinion of more than 50 professionals. Medical / welfare, transportation / warehousing, information and communications / information security, energy, the financial sector have been identified as promising industries. The results can be utilized in developing Big Data best practices thus contributing industrial development.

• Journal of Digital Convergence
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• v.15 no.4
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• pp.181-190
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• 2017

Recently, safety accidents of daily necessities such as humidifier disinfectant, mobile phones, and infant diapers, have occurred frequently. To protect consumers from these accidents, product safety management is required, and a product risk assessment tool is needed to evaluate the degree of safety of the product. In this paper, we have constructed RAS, which is a system that can evaluate product risk based on injury information of product accident in Korea Consumer Agency. RAS consists of an injury information analysis system for analyzing accident-related information and a risk assessment system for assessing risk using information derived from the system. The Bayesian network - based probabilistic method is applied to reflect the causal relationships that affect product risk in the risk assessment process. We used RAS to evaluate 33 children's products and compared them with the results of EU RAPEX RAG. Subsequent tasks include reducing the subjectivity of the input of the accident impact scale, and linking the above two systems.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.46 no.5
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• pp.101-110
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• 2009

The unconscious and non-intrusive measurements of activity signals or physiological signals represent important enabling technologies for realizing a ubiquitous healthcare environment as well as a related UI. Particularly, non-intrusive measurements should be used in activity monitoring system for long-term monitoring. This paper is based on activity estimation by measuring the activity signals of a user using a handhold device with an accelerometer. The user activity estimation system (UAES) presented in this paper makes non-intrusive measurements of activity signals to minimize inconveniencing a user and to create a more practical implementation in real life. Thus, a variety of positions in which the handhold device can be carried by a user for daily use is considered, such as in the front/hip/shirt pockets, a backpack, on the waist, and in the hand.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.45 no.8
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• pp.121-127
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• 2008

This paper presents an electric field distribution in a reverberation chamber using cylindrical diffuser. The characteristics of electric field distributions are compared with QRD(Quadratic Residue Diffuser) and cylindrical diffuser for $1{\sim}3$ GHz frequency band. The FDTD(Finite-Difference Time-Domain) method is used to analyze the field characteristics, and the field uniformity. At 2 GHz, the standard deviation and the tolerance of test volume in the reverberation chamber are improved by 0.11 dB, 0.43 dB for the case of cylindrical diffuser. The field strength is increased by 43.2 dBmV/m vs QRD's of 36.6 dBmV/m. Comparing with QRD's, the characteristic of polarization is also improved. These results show that reverberation chamber using cylindrical diffuser can be used alternative facility for measurement of electromagnetic interference and immunity.

• The Journal of the Convergence on Culture Technology
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• v.6 no.4
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• pp.203-208
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• 2020

The trade war between the United States and China has been going on for many years, and sanctions against Chinese telecommunications companies in the United States are increasingly tightening. Despite these restrictions, ZTE (Zhongxing), China's leading communication equipment company, is rather expanding its market share in the global 5th generation mobile communication (5G) market. ZTE's growth and competitiveness are based on its unique corporate culture. ZTE places great importance on R&D, has a corporate culture of humility and moderation based on traditional Chinese culture. Besides, it has the placement and use of human resources in the right place. While ZTE strives to implement people-centered management, it makes good use of internal competition. Despite ZTE's global market share and corporate competitiveness, virtually nothing has been studied in Korea. The results of this study are intended to be helpful in enhancing the competitiveness of Korea's ICT industry and companies that want to expand to the world while fostering 5G.

• Proceedings of the Materials Research Society of Korea Conference
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• 2009.05a
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• pp.13.1-13.1
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• 2009

Transparent electronics has attracted many interests, for it can open new applications for consumer electronics, transportation, business, and military. Among them, display backplane, thin film transistor (TFT) array would be the most attractive application. Many researchers have been investigating oxide semiconductors for transparent channel material of TFT since the report for transparent amorphous oxide semiconductor (TAOS) TFT by Hosono group and ZnO TFT by Wager group. Especially, oxide TFTs have been intensively investigated during a couple of years since the first demonstration of ZnO-TFT driving AM-OLED. Many papers regarding the fabrication and performance of oxide TFTs, and active matrix display driven by oxide TFTs have been reported. Now lots of people have confidence in the competitiveness of oxide TFTs for the backplane of AM-Display. Especially, high mobility, uniformity, fairly good stability, and low cost process make oxide TFTs applied even to a large size AM-OLED. Last year, Samsung mobile display, former SID, reported 12" AM-OLED driven by IZGO-TFT and it seems that the remained issue for the mass production is the bias temperature stability. Here, we will introduce the application of oxide TFT and important issue for oxide TFT to be used for the direct printing.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.6B
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• pp.650-662
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• 2011

The competition among companies in converged market of broadcasting and telecommunications has become severe. Companies in this market have vertically integrated critical resources by acquiring or strategically allying with relevant companies. However, the expansion of business territory accompanies financial, organizational, and technological risks. As such, it is important to identify critical success factors that highly affect the company's competency. This study is aimed at delivering strategic implications for firms playing in the converged market of broadcasting and telecommunications by drawing the priorities of competitive resources to acquire. To do this, we selected four teen specific core resources on CPNT (content- platform - network - terminal) value chain. Then, we conducted an Analytic Hierarchical Process (AHP) using data from experts in this industry. As a result, the priority for acquisition of competitive resources is presented as follows: broadcasting programs, implementation of TV application store, multi-platform, investment on wireless network, and diffusion of mobile devices. In addition, the result shows that the platform-centric vertical integration is the most promising strategy for competition.

• Proceedings of the Korea Contents Association Conference
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• 2008.05a
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• pp.591-594
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• 2008

Currently RFID code systems are classified into ISO, EPC, uCode, KKR code, Mobile RFID code, and etc. According to RFID code systems, RFID system is changed. For various RFID code systems, it's difficult to make it to the network and permanence of RFID business. And the existing system isn't add new RFID code systems to RFID system, and change it efficiently. This paper is proposed to a system of Multi RFID code Identification Translation using Ontology. This system is able to identify code data from RFID reader using ontology build into the identifier info and translation info of RFID code systems, and translate to URN data. Therefore in case of extending and changing RFID code systems, we can add and change the identifier info and translation info of RFID code systems in ontology.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.5
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• pp.49-55
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• 2016

To separate the CM and DM noise in the EMI generated in various electrical electronic systems, passive and active separators have been researched. These separators are an important part of an effective active EMI-filter. The passive separator has some advantages, in that it is easy to realize at a low price and its structure is very simple. However, its major drawback is that its accurate inductor realization and accurate core selection are very difficult. The active separator is smaller in size and more accurate, but its main drawback is that an op-amp which has a broad band frequency response is necessary, its cost is high, and a DC power circuit is required. This paper compares the characteristics of EMI filters which apply the existing passive separator and proposed active separator. It was concluded that an active separator is needed for expensive and accurate equipment, whereas a passive separator is sufficient for inexpensive and general purpose EMI filters.