• Journal of the Institute of Electronics Engineers of Korea SD
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• v.47 no.12
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• pp.55-67
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• 2010

The electrical properties of a back drilled via-hole (BDH) without the open-stub and the plated through via-hole (PTH) with the open-stub, which is called the conventional structure, in a high-count multi~layered (HCML) printed circuit board (PCB) were investigated for a high-speed digital system, and a selected inner layer to transmit a high-speed signal was farthest away from the side to mount the component. Within 10 GHz of the broadband frequency, a design of experiment (DOE) methodology was carried out with three cause factors of each via-hole structure, which were the distance between the via-holes, the dimensions of drilling pad and the anti-pad in the ground plane, and then the relation between cause and result factors which were the maximum return loss, the half-power frequency, and the minimum insertion loss was analyzed. Subsequently, the empirical formulae resulting in a macro model were extracted and compared with the experiment results. Even, out of the cause range, the calculated results obtained from the macro model can be also matched with the measured results within 5 % of the error.

• Communications of the Korean Mathematical Society
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• v.25 no.4
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• pp.623-628
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• 2010

Nakaoka and Oda ([1] and [2]) introduced the notion of maximal open sets and minimal closed sets in topological spaces. In this paper, we introduce new classes of sets called maximal $\theta$-open sets, minimal $\theta$-closed sets, $\theta$-semi maximal open and $\theta$-semi minimal closed and investigate some of their fundamental properties.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.32 no.6
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• pp.521-528
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• 2010

Purpose: Anatomical reduction of the fractured condylar process is an important prerequisite for re-establishing function. The authors reported about effectiveness of transoral approach for mandibular subcondyle fracture using trochar device in cases that the fracture line is below the reference line, the perpendicular line of the longitudinal axis of condylar process passing the lowest point of sigmoid notch. As a serial study, we report the open reduction via preauricular approach for mandibular condyle fracture, in cases that the fracture line is above the reference line. Patients and Methods: Sixteen condylar fractures of 15 adult patients were divided two groups and treated by open reduction via preauricular approach (8 cases) or by closed reduction (8 cases). The degree of maximal mouth opening, occlusion, anatomical reduction, condylar resorption and complications were assessed and evaluated for the two groups. Results: The open reduction of condyle via preauricular approach leads to good results without permanent complications. Anatomical reduction of open reduction group and maximal mouth opening range of the closed reduction group is significantly better than the other group. No significant differences were found in the condylar resorption and the occlusion. Conclusion: The preauricular approach was useful to reduce and fix the condylar fragment, in cases that the fracture line is above the reference line.

• Journal of the Microelectronics and Packaging Society
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• v.21 no.4
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• pp.117-123
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• 2014

Cu through-vias, which can be used as thermal vias or vertical interconnects, were formed using bottom-up electrodeposition filling as well as top-down electrodeposition filling into open via-holes and their microstructures were observed. Solid Cu through-vias without voids could be successfully formed by bottom-up filling as well as top-down filling with direct-current electrodeposition. While chemical-mechanical polishing (CMP) to remove the overplated Cu layer was needed on both top and bottom surfaces of the specimen processed by top-down filling method, the bottomup process has an advantage that such CMP was necessary only on the top surface of the sample.

• The Pure and Applied Mathematics
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• v.28 no.3
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• pp.199-215
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• 2021

The purpose of this paper is to define and study some new classes of sets by using nano operation namely, ζ-nano regular open, ζ-nano open, ζ-nano α-open, ζ-nano pre-open, ζ-nano semi-open, ζ-nano b-open and ζ-nano β-open in nano topology. Some properties and the relationships between these sets and the related concepts are investigated. Also, we found the deciding factors for the most common disease fever.

• Archives of Plastic Surgery
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• v.37 no.2
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• pp.161-168
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• 2010

Purpose: Surgical approaches to the condylar neck and subcondyle area can cause some morbidity such as, facial nerve injury, time-consuming nature and external scar etc. So many surgeons hesitate using open reduction and internal fixation for the treatment of subcondylar fractures. We report open reduction and internal fixation of subcondylar fractures in 13 adult patients via transmasseteric approach. Methods: From 2007 to 2009, 13 adults with subcondylar fracture of mandible were treated with open reduction and internal fixation via transmasseteric approach. A preauricular incision was extended downwards in a curvilinear fashion in the cervicomastoid skin crease. Skin flap was elevated above the SMAS layer. Masseter muscle was splitted at the anteroinferior edge of the parotid gland. After the fracture was reduced, fixed with appropriate plates and screws. All operation were performed under general anesthesia. Results: Mean follow-up period was 13.3 months. There were no signs and symptoms of facial nerve injury, difficulty in mouth opening, or malocclusion. Dissection time was roughly within 30 minutes. Conclusion: Transmasseteric open reduction and internal fixation of mandible subcondylar fracture can be performed with excellent visualization, and inconspicuous scar. It also offers swift access to the subcondylar area while substatially reducing the risk to the facial nerve and eliminating the complications associated with transparotid approaches.

• Journal of applied mathematics & informatics
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• v.40 no.1_2
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• pp.185-190
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• 2022

The aim of this article is to define fuzzy maximal open cover and discuss its few properties. we also defined and study fuzzy m-compact space and discussed its properties. Also we obtain few more results on fuzzy minimal c-regular and fuzzy minimal c-normal spaces. We have proved that a fuzzy Haussdorff m-compact space is fuzzy minimal c-normal.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.193-195
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• 2009

Bluetooth is a popluar wireless data transmission method with low power consumption. In this paper, we present a open source based player of video stream encoded by H.264 codec, which is transmitted via Bluetooth. An open source JM is used for H.264 decoding and modified for reading H.264 encoded data via Bluetooth. For display of decoded video data, SDL was utilized.

• Knowledge Management Research
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• v.19 no.2
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• pp.133-150
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• 2018

To cope with the rapid changes in the corporate environment, the creation of innovative output through various forms of collaboration have been discussed. For open collaborations, contributors who distribute to various countries and cultures are able to share knowledge via the internet without physical rewards or responsibilities. In this study, we focused on the open source software project, which is a representative open collaboration. We investigated the factors that affect the knowledge contribution of developers of various countries within the open collaboration platform. Specifically, we investigated the open collaborative nature of multi-culture developers by dividing cultures according to collectivism and individualism. We collected data on 26,604 developers using a python based web crawler for GitHub which is an open source software development platform, and conducted cross-cultural study. This paper contributes to the field of knowledge management by suggesting various impacts of antecedents such as hireability, and information exposure on knowledge sharing according to culture.

• Proceedings of the KSRS Conference
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• 1999.11a
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• pp.84-88
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• 1999

Recently, the necessity of accessing spatial data from remote computer via network has been increased as distributed spatial data have been increased due to their size and cost. Many methods have been used in recent years for transferring spatial data, such as socket, CORBA, HTTP, RPC, FTP, etc. In this paper, we propose spatial clearinghouse components to access distributed spatial data sources via CORBA and Internet. The spatial clearinghouse components are defined as OLE/COM components that enable users to access spatial data that meet their requests from remote computer. For reusability, we design the spatial clearinghouse with UML and implement it as a set of components. In order to enhance interoperability among different platforms in distributed computing environment, we adopt international standards and open architecture such as CORBA, HTTB, and OpenGIS Simple Features Specifications. There are two kinds of spatial clearinghouse: CORBA-based spatial clearinghouse and Internet-based spatial clearinghouse. The CORBA-based spatial clearinghouse supports COM-CORBA bridge to access spatial data from remote data providers that satisfy the OpenGIS Simple Features Specification for OLE/COM using COM and CORBA interfaces. The Internet-based spatial clearinghouse provides Web-service components to access spatial data from remote data providers using Web-browser.