• Journal of the Chungcheong Mathematical Society
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• v.16 no.2
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• pp.79-88
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• 2003

In this paper, we study properties of a free normalizing extension ring of a FI-extending ring. We develop properties of formal triangular matrix rings and FI-extending rings. Several results on the quasi-extending modules are obtained.

• Journal of the Korean Mathematical Society
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• v.49 no.3
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• pp.503-514
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• 2012

The concepts of t-extending and t-Baer for modules are generalized to those of FI-t-extending and FI-t-Baer respectively. These are also generalizations of FI-extending and nonsingular quasi-Baer properties respectively and they are inherited by direct summands. We shall establish a close connection between the properties of FI-t-extending and FI-t-Baer, and give a characterization of FI-t-extending modules relative to an annihilator condition.

• Kyungpook Mathematical Journal
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• v.60 no.1
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• pp.45-51
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• 2020

A module M is called FI-extending if every fully invariant submodule of M is essential in a direct summand of M. In this work, we define a module M to be generalized FI-extending (GFI-extending) if for any fully invariant submodule N of M, there exists a direct summand D of M such that N ≤ D and that D/N is singular. The classes of FI-extending modules and singular modules are properly contained in the class of GFI-extending modules. We first develop basic properties of this newly defined class of modules in the general module setting. Then, the GFI-extending property is shown to carry over to matrix rings. Finally, we show that the class of GFI-extending modules is closed under direct sums but not under direct summands. However, it is proved that direct summands are GFI-extending under certain restrictions.

• Journal of Communications and Networks
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• v.18 no.3
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• pp.476-483
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• 2016

Super Wi-Fi is a Wi-Fi-like service exploiting TV white space (WS) which is expected to achieve larger coverage than today's Wi-Fi thanks to its superior propagation characteristics. Super Wi-Fi has been materialized as an international standard, IEEE 802.11af, targeting indoor and outdoor applications, and is undergoing worldwide field tests. This paper demonstrates the true potential of indoor Super Wi-Fi, by experimentally comparing the signal propagation characteristics of Super Wi-Fi and Wi-Fi in the same indoor environment. Specifically, we measured the wall and floor attenuation factors and the path-loss distribution at 770MHz, 2.401 GHz, and 5.540 GHz, and predicted the downlink capacity of Wi-Fi and Super Wi-Fi. The experimental results have revealed that TVWS signals can penetrate up to two floors above and below, whereas Wi-Fi signals experience significant path loss even through a single floor. It has been also shown that Super Wi-Fi mitigates shaded regions of Wi-Fi by providing almost-homogeneous data rates within its coverage, performs comparable to Wi-Fi utilizing less bandwidth, and always achieves better spectral efficiency than Wi-Fi. The observed phenomena imply that Super Wi-Fi is suitable for indoor applications and has the potential of extending horizontal and vertical coverage of today's Wi-Fi.

• The KIPS Transactions:PartA
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• v.17A no.3
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• pp.137-144
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• 2010

Recently, as the consumer market of the mobile device is explosively getting bigger and bigger, both of the usability and applicability of the mobile device are also growing rapidly. The customers prefer to transfer data between the different mobile devices and download multimedia data via the wireless connection even wherever they are. The trend of mobile devices also shows the tendency of employing the various connectivity technologies such as Bluetooth, Wi-Fi, W-USB, NFC, and so on in a single mobile device. With this market trend, the importance of the technology associating different devices is getting increased gradually. In this paper, we present how to support the NFC association of the W-USB technology by extending the existing NFC's handover protocol. We also explain the differences between the NFC association and the handover protocol, and propose the method to resolve the differences by extending the handover protocol of the NFC technology. Finally, we describe how to implement the NFC system supporting the W-USB handover protocol.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.13 no.2
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• pp.106-115
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• 2013

LED lighting control system using unidirectional DMX512 (digital multiplex with 512 pieces of information)) protocol has been the most popular. Nowadays, the user's consumption has been upgrading to the more intelligent system but the upgrading process does not affect the existing infrastructure. There were many researches use the additional communication for the feedback communication way such as WiFi, Controller Area Network (CAN), Power Line Communication (PLC), etc but all researches had inherent disadvantages that created the independent feedback with the existing DMX512 system. Our paper represents the novel method that uses the remote device management (RDM) protocol to associate the additional feedback with existent DMX512 infrastructure in the one system. The data in DMX512 frame sending to the DMX512 client is split and repacked to become the RDM packet. This RDM packet is transferred to the RDM monitor console and the response RDM packet is converted to the DMX512 frame for control DMX512 client devices. This is the closed loop control model which uses the bidirectional convertibility between RDM packet and DMX512 frame. The proposed method not only upgrades the feedback control function for the old DMX512 system without changing the existent infrastructure, but also solves compatible problems between new RDM devices and old DMX512 devices and gives the low cost solution for extending DMX512 universe.

• Journal of Chest Surgery
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• v.24 no.12
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• pp.1185-1191
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• 1991

The clinical and pathological analysis of solitary pulmonary nodules were estimated in 35 patients with nodules who were surgically resected at the Dept. of Thoracic and Cardiovascular Surgery of Chonnam National University Hospital from July 1978 to Aug. 1989. The results were as follows: 1. Mean age of patients was 43.5 years extending from 11 years to fi7 years old and male to female ratio was 6: l. 2. Preoperative symptoms were complained of dull pain in the chest, cough, hemoptysis and general weakness in 69% of patients. 3. The histopathologic findings of surgically resected nodules showed benign nodule in 51% and malignancy 49%. The most frequent diseases were granuloma[67%] in benign nodules and squamous cell carcinoma[76%] in malignancy. In topographical region of nodules in the lung, benign granuloma was more prevalent in upper lobes, while malignancy was slightly more frequent in lower lobes. 4. The incidence of malignancy by age was extremely rare in patients with less than 35 years old, but in greater than 35 years of age, malignancy comprised up to 67% of patients. 5. Complications of thoracotomy were minor bleedings, wound infections and chest pain not to be required any reoperation except one patient died of sudden onset of arrhythmia after pneumonectomy.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.5
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• pp.1702-1707
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• 2010

As quantities of the data that transmitting by the wireless are more increased, the interest and application are extending about 802.11n that uses by combination two existing 20MHz wireless LAN Channel. 802.11n use dual band of 2.4GHz band and 5.8GHz. So this is expected in mass wireless transmission method because of interference evasion effect in compliance with the radio communication of existing 2GHz neighborhood band. Like this 802.11n uses the radio as well and transmits information there is not only a possibility of undergoing an influence in radio wave environment of circumference. Specially the interior environment and outdoor environment is a possibility of saying that will be defined with each other different modeling as affects in radio communication is different. In this paper, we'll compare the influence to RF feature (802.11n) by (Indoor/Outdoor) environment difference through compared with 802.11n RF feature and Network feature in (Indoor/Outdoor) environment and also examine the correlation between RF feature and Network feature.