• Journal of Broadcast Engineering
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• v.16 no.5
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• pp.834-845
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• 2011

Massive broadcasting contents such as UHD(Ultra High Definition) TV which requires multi-channel capacity for transmission has been introduced in recent years. A transmission scheme with channel bonding has been considered for transmission of massive broadcasting contents. In HFC(Hybrid Fiber Coaxial) networks, DOCSIS 3.0(Data Over Cable Service Interface Specification 3.0) has already applied channel bonding schemes for up/downstream of data service. A method unlike DOCSIS 3.0 is required to introduce a channel bonding scheme in the broadcasting service having unidirectional transmission with a downstream. Since a massive broadcasting content requires several channels for transmission, VBR(Variable Bit Rate) transmission has been emerging for the bandwidth efficiency. In addition, research on channel allocation and resource scheduling is required to guarantee QoS(Quality of Service) for the broadcasting service based on VBR. In this paper, we propose a transmission method for mass broadcasting service in HFC network and show the UHD transmission simulator developed to evaluate the performance. In order to evaluate the performance, we define various scenarios. Using the simulator, we assess the possibility of channel bonding and VBR transmission for UHD broadcasting system to provide mass broadcasting service efficiently. The developed simulator is expected to contribute to the efficient transmission system development of mass broadcasting service.

• Journal of Dental Rehabilitation and Applied Science
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• v.26 no.1
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• pp.59-68
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• 2010

Recently, dental implants extensively inserted on edentulous area show highly clinical success rate. However, clinicians cannot exclude the possibility of failure and it often unexpectively occures. Many possible factors associated with failure of dental implants have been reported but controversy exists over the extent to them. In this study, we collected 212 patients who had been inserted 358 dental implants on mandibular premolar and molar area from 2005 to 2006. The survival rate of fixtures was recorded according to age of patients, implantation site, implant system, diameter and length of fixtures. Multi-variable analysis using SPSS chi-square test was operated to verify relation of each factors and survival rates. Accumulative survival rate was 98.3% for 3 years. Only diameter of fixtures was related to the implant survival rate. This may be thought that wider fixtures had been chosen to rescue implants or used in sites of poor bone quality. Further continuous study will be needed for direct guidance associated with survival rate of implants.

• Restorative Dentistry and Endodontics
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• v.32 no.1
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• pp.9-18
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• 2007

The purposes of this study were to examine the variability of adhesive thickness on the different site of the cavity wall when used total-etch system without filler and simplified self-etch system with filler and to evaluate the relationship between variable adhesive thickness and microtensile bond strength to the cavity wall. A class I cavity in six human molars was prepared to expose all dentinal walls. Three teeth were bonded with a filled adhesive, $Clearfil^{TM}$ SE bond ana the other three teeth were bonded with unfilled adhesives, $Scotchbond^{TM}$ Multi Purpose. Morphology and thickness of adhesive layer were examined using fluorescence microscope. Bonding agent thickness was measured at three points along the axial cavity wall edge of cavity margin (rim). halfway down each cavity wall (h1f), internal angle of the cavity (ang). After reproducing the adhesive thickness at rim, h1f and ang, micro-tensile bond strength were evaluated. For both bonding agents, adhesive thickness of ang was significantly thicker than that of rim and h1f (P <0.05). As reproduced the adhesive thickness, microtensile bond strength was increased as adhesive thickness was increased in two bonding agents. Adhesive thickness of internal angle of the cavity was significantly thicker than that of the cavity margin and the halfway cavity wall for both bonding agents. Microtensile bond strength of the thick adhesive layer at the internal angle of the cavity was higher than that of the thin adhesive layer at 1,he cavity margin and the halfway cavity in the two bonding systems.

• JSTS:Journal of Semiconductor Technology and Science
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• v.17 no.1
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• pp.56-64
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• 2017

In this paper, an advanced ZigBee (AZB) system for internet-of-things (IoT) applications is proposed which can support various data rates from 31.25 Kbps to 2 Mbps, and the implementation results of the AZB baseband processor are presented. Repetition coding for 32-chip direct-sequence spread spectrum (DSSS) symbol is applied for low rates under 250 Kbps to extend the coverage. Convolution coding, puncturing, and interleaving for non-DSSS symbol are performed for high rates from 500 Kbps to 2 Mbps for multi-media services. Simulation results show that the coverage increases at the rate of 51.8-77.3% for various environments compared with IEEE 802.15.4 ZigBee. AZB baseband processor was implemented in 180 nm CMOS process and total gate counts are 260K with the size of $5.8mm^2$.

• Proceedings of the KIEE Conference
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• 2005.10b
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• pp.152-154
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• 2005

In this paper, we propose a new architecture of Fuzzy Polynomial Neural Networks(FPNN) by means of genetically optimized Fuzzy Polynomial Neuron(FPN) and discuss its comprehensive design methodology involving mechanisms of genetic optimization, especially Genetic Algorithms(GAs). The design of the network exploits the extended Group Method of Data Handling(GMDH) with some essential parameters of the network being provided by the designer and kept fixed throughout the overall development process. This restriction may hamper a possibility of producing an optimal architecture of the model. The proposed FPNN gives rise to a structurally optimized network and comes with a substantial level of flexibility in comparison to the one we encounter in conventional FPNNs. It is shown that the proposed genetic algorithms-based Fuzzy Polynomial Neural Networks is more useful and effective than the existing models for nonlinear process. We experimented with Medical Imaging System(MIS) dataset to evaluate the performance of the proposed model.

• International Journal of Human Ecology
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• v.1 no.1
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• pp.1-14
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• 2000

Parental satisfaction is the foundation of a happy family. It is a key factor in overall life satisfaction and also a critical variable in the development of children, and thus an education program aimed at parental satisfaction improvement is needed. This study attempts to determine basic elements of parental satisfaction that could enable better parental education programs. To accomplish this, mother's parental satisfaction and factors related to it were examined. The subjects were 641 mothers of primary school and middle school students aged 10, 12, and 14 residing in Seoul, Pohang and Kwangyang. Structured self-administered questionnaires were used to ascertain mothers' parental role satisfaction, mothers' role values, children related variables, mother related variables, father related variables, and home environment variables. The findings indicate that the variables related to parental satisfaction are multi-dimensional, that mothers' parental satisfaction can be improved by other family member's effort, and that a family's external characteristics are less important than its internal characteristics. These results imply that it is essential to include the characteristics of the family system when designing parental education programs. Furthermore, the role of specific family members, namely the husband, should be expanded in more supportive ways in Korean families to improve mothers parental satisfaction.

• Journal of Distribution Science
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• v.14 no.12
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• pp.53-59
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• 2016

Purpose - The concept of lifetime job has disappeared, and men are interested in business foundation to work continuously with similar jobs. The value of business foundation is thought to be important in accordance with the viewpoint of society, government, individuals and family. Research design, data, and methodology - The economic exchange between South Korea and China has been expanded, and they are likely to play an important role in entry into China by business foundation in accordance with economic exchange between the two countries. As Korean residents inflow overseas, small businessmen business foundation shall be given attention scientifically and Korean Chinese business foundation shall be given attention as well. Results - The study investigated the effects on psychological characteristics and small business foundation motives upon business foundation will by using models. Self-efficacy and self achievement had positive influence upon small business foundation of Korean Chinese. The use of control variable had explanatory power (29.6%). Conclusions - The findings would help the government's small business foundation system to promote small business foundation and to be a guide for expansion in Korean Chinese's small business markets. An education program should be developed to strengthen Korean Chinese's self efficacy considering psychological characteristics.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.6 no.6
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• pp.885-890
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• 2002

Turbo compressor needs high speed rotation of impeller in structure, high rated gearbox and conventional induction motor. This mechanical system increased the moment of inertia and mechanical friction loss. Resently the study of turbo compressor applied super high speed motor and drive, removing gearbox made its size small and mechanical friction loss minimum. In this study we tried to develope variable super high speed motor controller, compressor controller and MMI controller under one DSP based systems for 1500Hp, 70,000rpm direct drive Turbo compressor. It have to do unitification of each controller"s hardware and software. The result of study is applied to a 150Hp direct turbo compressor and makes it goods.oods.

• Korean Medical Education Review
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• v.15 no.3
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• pp.120-124
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• 2013

The clinical clerkship focuses students on developing their ability to perform comprehensive diagnosis and management of patients with common undifferentiated problems by the integration of knowledge and clinical reasoning. Therefore, the clerkship evaluation system should assess their actual problem solving and professional behavior. However, concern remains that clerkship evaluations are imprecise and highly variable. This review is designed to provide faculty members with concepts, options, and a methodology to actively teach and evaluate the clinical clerkship, as well as offer encouragement and inspiration to medical students. We reviewed past and current clinical clerkship evaluations and discuss several tips to improve clinical excellence such as continuity, transparency of the evaluation process, a faculty development program, practical examination of clinical skills, implementation of a checklist for recording exposure and skills, providing prompt and constructive feedback to students, self-evaluation of professional performance, varying multi-faceted assessment combinations, being outpatient clinic-centered, and having dedicated faculty members who give students one-on-one contact with a preceptor.

• The Korean Journal of Cytopathology
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• v.16 no.2
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• pp.110-114
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• 2005

Primary leptomeningeal glioblastomatosis is a rare and fatal tumor of the central nervous system, the condition is characterized by diffuse infiltration of the tumor in the meninges without evidence of primary tumor within the brain or spinal cord. We reported an unusual case of leptomengial glioblastomatosis, which was detected by the consecutive cerebrospinal fluid (CSF) cytology with application of immunohistochemistry, in addition to its cytologic findings. A healthy 21 year old man, who was enlisted in the army, presented with a stuporous mental state and diffuse enhancement of meninges without evidence of primary mass lesion in the brain and spinal cord on magnetic resonance imaging(MRI). CSF cytology showed small loose clusters of tumor cells with single cells and lymphocytes. The tumor showed variable pleomorphism with coarse chromatin, irregular nuclear membranes and multi lobated nuclei. On immunohistochemical staining, the tumor cells were founded to be positive for GFAP. In conjunction with radiologic findings, brain biopsy confirmed the diagnosis of leptomenigeal glioblastomatosis. The use of immunohistochemistry is helpful in confirming CSF cytologic diagnosis in patients with primary leptomeningeal glioblastomatosis.