• 한국멀티미디어학회논문지
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• 제8권12호
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• pp.1572-1580
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• 2005

The common requirements for watermarking are usually invisibility, robustness, and capacity. We proposed the watermarking for 3D mesh model based on projection onto convex sets for invisibility and robustness among requirements. As such, a 3D mesh model is projected alternatively onto two convex sets until it converge a point. The robustness convex set is designed to be able to embed watermark into the distance distribution of vertices. The invisibility convex set is designed for the watermark to be invisible based on the limit range of vertex movement. The watermark can be extracted using the decision values and index that the watermark was embedded with. Experimental results verify that the watermarked mesh model has both robustness against mesh simplification, cropping, affine transformations, and vertex randomization and invisibility.

• 한국멀티미디어학회논문지
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• 제10권12호
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• pp.1551-1558
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• 2007

The standard of evaluating function of speech coder for mobile telecommunication can be shown in channel capacity, noise immunity, encryption, complexity and encoding delay largely. This study is an algorithm to reduce complexity applying to CDMA(Code Division Multiple Access) mobile telecommunication system, which has a benefit of keeping the existing advantage of telecommunication quality and low transmission rate. This paper has an objective to reduce the computing complexity by controlling the frequency band nonuniform during the changing process of LSP(Line Spectrum Pairs) parameters from LPC(Line Predictive Coding) coefficients used for EVRC(Enhanced Variable-Rate Coder, IS-127) speech coders. Its experimental result showed that when comparing the speech coder applied by the proposed algorithm with the existing EVRC speech coder, it's decreased by 45% at average. Also, the values of LSP parameters, Synthetic speech signal and Spectrogram test result were obtained same as the existing method.

• 한국자동차공학회논문집
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• 제7권6호
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• pp.165-173
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• 1999

HILS system consists of hardwares which are engine and dynamometer and softwares which is vehicle model without the engine. It is well-known that because of engines's nonlinearity it is difficult to describe an engine exactly and not to lose it reality coincidently. But HILS system is the high technology that can compensate this weakness by using a real engine instead of model. The various experiments regarding the ACC which are not normally available for real vehicle tests have been performed by the HILS system. From the results , the HILS system is expected to decrease the experimental accident rate and save costs and time. Compared with simulation, HILS experimental results show similarities and expected to increase road capacity.

• 대한산업공학회지
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• 제30권4호
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• pp.277-284
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• 2004

CDMA (Code Division Multiple Access) is a promising air interface technique for digital cellular systems. The soft handoff between base stations is one of many important features of CDMA for the mobile stations crossing the cell boundaries. The service areas of MSC's (Mobile Switching Centers) are defined as the unions of the service areas of the base stations connected to MSC's and are assumed to have hexagonal shapes. An analytical approach to the performance analysis of the link between MSC's for supporting the inter-MSC soft handoff scheme will be developed to obtain the probability that a soft handoff to an adjacent MSC will be blocked due to the shortage of the link capacity. Also, the rate of new connection establishments that are requested by the mobile stations moving to the service area of an MSC according to the inter-MSC soft handoff scheme will be obtained.

• 유통과학연구
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• 제11권3호
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• pp.13-22
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• 2013

Purpose - Product purpose for optimal values solution for synthesize evaluative criteria and optimize product design values. In addition, product designer has to consider the product design to conform to project, laws and regulations, authentication, from the product design stage. Research design, data, methodology - How to use an evaluative criteria model's imprecise market data by evaluative criteria research design; product mapping relationships between design parameters and customer requirements using product predicted value method. An evaluative criteria model and their associated criteria status, product evaluative criteria model of results. Results - Therefore, after the enterprise product design project analysis, effectiveness and the customer degree of satisfaction must be appraised to obtain the maximum value for the benefit on behalf of the implementation goals, the promotion product level and market competition strength. Conclusions - In multi criterion decision making (MCDM), using its searching software capacity to obtain the optimal solution.

• 설비공학논문집
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• 제13권4호
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• pp.233-241
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• 2001

In the present study, various experiments were performed to investigate the capacity modulation and transient response control using a variable speed compressor and electronic expansion valve(EEV). Based on the experimental results, the operation control algorithm and real time digital control system were constructed to adjust the superheat at the inlet of the compressor. Superheat control was fulfilled using both the PI feedback controller and PI controller combined with a feedforward concept. As a result, the tracking performance of the latter was better than that of former.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1998년도 하계종합학술대회논문집
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• pp.38-41
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• 1998

Due to the increasing demand to multimedia services over wireless communication network, LMDS(Local Multipoint Distribution Service) has been proposed as an alternate approach for broadband wireless access network. But LMDS, Which uses the mmwavelength radio spectrum, has been limited for unknown microwave frequency characteristics. In this paper, we analyze the parameters related to the system design on 28GHz frequency: Propagation path loss and rainfall attenuation. Based on these analytical results, the proper cell size in Korea is determined. We also analyze the bit error rate and frame loss rate for various kinds of digital modulation schemes(QAM 4, 16, 64, 256). Finally, we apply to ㅍ service to evaluate a call blocking rate, efficiency and channel capacity.

• 한국디지털정책학회:학술대회논문집
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• 한국디지털정책학회 2004년도 춘계학술대회
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• pp.355-367
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• 2004

Interest about information infrastructure construction is decayed socially according to arrival of information age, and various information systems is constructed for efficient business processing, customer service improvement in public sector. According to subjective method of performance improvement for information system of public sector and engine that propel information system construction bemuse it is no definite hardware sizing guidelines for introduction or system caterer, is calculating resources scale of information system. Is situation that problem of excess of scale or reduction sizing is happening, and is causing various kinds problem that is waste of information budget and service decline thereby. So, We proposed hardware sizing framework for information system that is applied to information programs.

• Journal of Information Technology Applications and Management
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• 제15권3호
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• pp.261-273
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• 2008

The starting point of knowledge generation and management is the enhancement of learning capability and capacity of organizational members. Organizational change for learning environment should be aligned with the change of organizational strategy, structure and processes. The study employed action learning methodology to constitute learning organization processes. The treatment effect to institute learning organization has been successful thanks to the members' zeal and consensus to change the processes. However, not every learning team has been so successful. Some cases complained time consuming where others expect to be helpful for their incentives. The researchers concluded that the most important point for success of the learning organization project should be the support of top management.

• Journal of information and communication convergence engineering
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• 제18권3호
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• pp.183-187
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• 2020

The general Wi-Fi network connection structure is that a number of IoT (Internet of Things) sensor nodes are directly connected to one AP (Access Point) node. In this structure, the range of the network that can be established within the specified specifications such as the range of signal strength (RSSI) to which the AP node can connect and the maximum connection capacity is limited. To overcome these limitations, multiple middleware bridge technologies for dynamic scalability and load balancing were studied. However, these network expansion technologies have difficulties in terms of the rules and conditions of AP nodes installed during the initial network deployment phase In this paper, an intelligent edge computing IoT device is developed for constructing an intelligent autonomous cluster edge computing network and applying it to real-time road danger context aware and notification system through an intelligent risk situation recognition algorithm.