• Title/Summary/Keyword: Variable Structure Control

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A Study on the Chinese Consumers' Purchase Intention of Digital Music Using an Extended Model of Goal-directed Behavior (EMGB) : Focused on Mobile Digital Music (확장된 목표지향적 행동모형을 적용한 중국인들의 디지털음악 구매의도에 관한 연구: 모바일 디지털음악을 중심으로)

  • Peng, Min;Bae, So Young
    • The Journal of the Korea Contents Association
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    • v.20 no.9
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    • pp.332-343
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    • 2020
  • As a study on the purchase intention of digital music, the research applied the Extended Model of Goal-directed Behavior(EMGB) with the perceived value and empirically evaluated the impact of variables such as attitude, subjective norms, positive and negative anticipated emotions, perceived behavioral control and desire on the purchase intention. The study was conducted using a survey data collected from valid questionnaires of 342 copies aimed at Chinese mobile music application users and employed the structure equation model. The findings indicate that attitude, negative anticipated emotions, perceived behavioral control towards digital music purchasing and the frequency of past behavior positively influenced users' desire for digital music purchasing. Another result has been confirmed that perceived value, which was an added variable, showed a significant impact on attitude. Along with the frequency of past behavior and desire, perceived value also exerted positive influence on purchase intention.

Design of DC Level Shifter for Daisy Chain Interface (Daisy Chain Interface를 위한 DC Level Shifter 설계)

  • Yeo, Sung-Dae;Cho, Tae-Il;Cho, Seung-Il;Kim, Seong-Kweon
    • The Journal of the Korea institute of electronic communication sciences
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    • v.11 no.5
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    • pp.479-484
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    • 2016
  • In this paper, a design of DC level shifter transmitting and receiving control and data signal which have various DC level through daisy chain interface between master IC and slave is introduced in the cell voltage monitoring (CVM). Circuit designed with a latch structure have a function to operate in high speed and for output of variable DC level through transmission gate. As a result of the simulation and the measurement, it was confirmed that control and data signal could be transferred according to the change of DC level from 0V to 30V. Delay time was measured about 170ns. but, it was considered as a negligible tolerance due to a parasitic capacitance of measuring probe and test board.

Joint wireless and computational resource allocation for ultra-dense mobile-edge computing networks

  • Liu, Junyi;Huang, Hongbing;Zhong, Yijun;He, Jiale;Huang, Tiancong;Xiao, Qian;Jiang, Weiheng
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.14 no.7
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    • pp.3134-3155
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    • 2020
  • In this paper, we study the joint radio and computational resource allocation in the ultra-dense mobile-edge computing networks. In which, the scenario which including both computation offloading and communication service is discussed. That is, some mobile users ask for computation offloading, while the others ask for communication with the minimum communication rate requirements. We formulate the problem as a joint channel assignment, power control and computational resource allocation to minimize the offloading cost of computing offloading, with the precondition that the transmission rate of communication nodes are satisfied. Since the formulated problem is a mixed-integer nonlinear programming (MINLP), which is NP-hard. By leveraging the particular mathematical structure of the problem, i.e., the computational resource allocation variable is independent with other variables in the objective function and constraints, and then the original problem is decomposed into a computational resource allocation subproblem and a joint channel assignment and power allocation subproblem. Since the former is a convex programming, the KKT (Karush-Kuhn-Tucker) conditions can be used to find the closed optimal solution. For the latter, which is still NP-hard, is further decomposed into two subproblems, i.e., the power allocation and the channel assignment, to optimize alternatively. Finally, two heuristic algorithms are proposed, i.e., the Co-channel Equal Power allocation algorithm (CEP) and the Enhanced CEP (ECEP) algorithm to obtain the suboptimal solutions. Numerical results are presented at last to verify the performance of the proposed algorithms.

Mesh Refinement for Isogeometric Analysis and Post-Processing (등기하 해석을 위한 요소망 정제와 후처리 방법)

  • Kim, Jee-In;Luu, Tuan Anh;Lee, Jae-Hong;Kang, Joo-Won
    • Journal of Korean Association for Spatial Structures
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    • v.12 no.2
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    • pp.45-53
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    • 2012
  • This paper derives Isogeometric analysis and post-processing method of surface that are generated by NURBS basis function for accurate geometric modeling and structure analysis of free-form. By deforming these parameters that are consisted of control points, knots, polynomial, variable geometric models are derived. The basis function that is used to Isogeometric analysis is same to the basis function of NURBS that is used to generate geometric models. For performing isogeometric analysis, h-p-k refinement is performed without changing of original geometry. To visualize the results of isogeometric analysis that control points' displacements, post-processing method that is the interface method between IGES format and Rhinoceros is derived.

Two-stage Adaptive Digital AGC Method for SDR Radio (SDR 통신장비를 위한 2단계 적응형 Digital AGC 기법)

  • Park, Jong-Hun;Kim, Young-Je;Cho, Jung-Il;Cho, Hyung-Weon;Lee, Young-Po;Yoon, Seok-Ho
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.37 no.6C
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    • pp.462-468
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    • 2012
  • In this paper, an adaptive digital automatic gain control(AGC) algorithm with two stages is proposed. AGC technique is crucial for mobile communication equipment because path loss in wireless channel and gain fluctuation in receiver front-end continuously change the received signal strength. Furthermore, adaptive criteria should be applied to the design of AGC algorithm in order to support many waveforms with one SDR communication device. With these reasons, a two-stage structure is proposed to satisfy both flexibility and adaptiveness. Compared with conventional method, it also requires shorter convergence time. Numerical results show that the gain value of variable gain amplifier(VGA) is converged within proper time and proposed scheme controls the input level of analog to digital converter(ADC) to be stable during long range of time.

The development and operation characteristics analysis of PCS applied PV Output Senseless (POS) MPPT (PV Output Senseless (POS) MPPT 제어법이 적용된 단상 PCS 개발 및 운전특성 분석)

  • Lee, Seok-Ju;Park, Hae-Yong;Kim, Gyeong-Hun;Seo, Hyo-Ryong;Park, Min-Won;Yu, In-Keun
    • Proceedings of the KIEE Conference
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    • 2007.07a
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    • pp.226-227
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    • 2007
  • The purpose of this study for photovoltaic (PV) generation system is to keep the output power of photovoltaic cells maximized under any weather conditions. In a conventional MPPT (Maximum Power Point Tracking) control method, both voltage and current coming out from PV array have to be fedback. Thus, the system has a complex structure, and may fail to track MPP of PV array when unexpected weather conditions happen. This paper proposes a novel PV Output Senseless (POS) control method to solve the mentioned problem. The main advantage of this method is that the current flowing into load is the only one considerable factor. In case of a huge PV generation system, it can be operated much more safely than the conventional system. To verify this theory, results that compare and analyze the simulated data with experimental data under real weather condition of the manufactured PV generation system are shown in this paper. Authors vividly states that this theory uses constant resistors and variable resistors of DC-DC converter in PV system. Authors emphasize that it is a very useful method to maximize power from PV cells to load with only the feedback of load current. Authors also emphasize that this theory is applicable in case of the PCS in PV power generation system.

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A Study on Marketing of Cultured Laver Products (양식해태의 유통에 관한 조사 연구)

  • 유충열
    • The Journal of Fisheries Business Administration
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    • v.4 no.1_2
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    • pp.19-57
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    • 1973
  • Laver io one of the most necessary and seasonal items in Korean food from oldtimes. Laver is lagely eaten in dried form, and its supply depends entirely upon culture weeds. The history of laver culture in Korea about sixty or seventy years is older than in Japan. Significance of laver culture is divided into two aspects, one is food supply in the nation, and the other is export to other countries. Houses engaged in laver culture are about foully thousands, and laver production in 1972 is estimated as 1, 3 bitten sheets. (1 sheet is a dried laver of 20 cm sq, in the shape of paper) Especcially meaning of layer production is the concentration of labour input, and systematic management of labour. From around 1920, the method of laver culture was introduced by Japanese Imperialism for mono culture in shallow seas, and mass products of laver is provided to Japan market, DOMESTIC MARKET Fundamental consume function calculates at below, $D_{(68_71)}$=16354 $Y^{0.471}$ $P^{-1.0662}$ where D is total layer demand, Y income variable, P price variable. It means income elasticity is 476. in the whole country, and price elasticity is 1, 07. But generally income elasticity is higher in urban area than in rural area, as shown at 1, 3 in Seoul city. Expence of laver in house expenditure is mutually correlated with another expence, See Table 12 about the relative function. See Table 14 and 16 about the relation between the gathering and the changes of price in auction, wholesale and retail price support system is for two effects, one of which is constraint of the upper price, the other is rise of the lower price. Before the system control, the equation in three year average calculated as below, $Y_{b}$ =18, 907.7455+15435.9364 t (r=0.89) where the origin t=0 is the November and the units are month. Post the system control, $Y_{p}$ =30, 047.9636+1, 631.1721t (r=0.97) therefore, this system has an effect only on the rise of lower price, Average annual margins of laver products at four market levels according to the consumer spent is below. EXPORTING MARKET Japanese demand function of laver products is, Log D=5, 289+1, 108 Log Y-1, 395 Log P (r=0.987) where D is Japanese laver demand, Y income variable, P price variable. according to which income elasticity is 1. 1 and price elasticity is 1.4. Laver production in 1970 tile highest record till then, is estimated as six billion sheets. But the recent improvement of laver culture techniques, the production of seeds and freezing storage of seeds has been stabilized. Futher new culture farms have been developed by means of break- water fences or by floating culture method. These improvements have been backed up with increased demand of laver products. Import quantity and price of Korean laver products are restrained by three organizations, that is producer, distributor and consumer. This relationship calculated by regression equation shows that import is influenced only producer organization, at the sacrifice of consumer profit. For increase to export of laver products, we urgently require to open foreign trade of laver products for Japanese consumer, .and Japan has political responsibility to solve Korean laver structure. But with long run timeseries, as regards Japanese production and import quantity, importing function shows increasing trend as below, 250 million sheets <3, 947.1674+0.005 $L_{g}$ >) 600 million sheets where $L_{q}$ is relative production quantity of laver in Japan. (unit; 100 thousand sheets) Our Export effort should be put on the highly processed products whithin the restraind quote.ote.

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Construction and Validation of Infection Control Practice Scale for Dental Hygienist (치과위생사의 감염관리 실천도 측정도구의 개발과 타당화)

  • Cho, Young-Sik;Jun, Bo-Hye;Choi, Young-Suk
    • Journal of dental hygiene science
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    • v.9 no.1
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    • pp.53-59
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    • 2009
  • Infection control is now recognized as an important quality indicator in dental health service setting. The purpose of this study was to develop and validate Dental Hygienist's Infection Control Practice Scale for quality management of dental health service in Korea. The data of 254 dental hygienists was subjected to exploratory factor analysis using SPSS 16.0 and confirmatory factor analysis using AMOS 16.0. The total items of preliminary scale were 21 items and 5 subscale. Principal component analysis was completed with Varimax rotation. The results show a change in factor structure from 5 factor solution to 4 factor solution. The confirmatory factor analysis confirmed the four subscales(Immunization and periodic tests, Clinical procedure, Handwashing, Personal protection) which have a total of 12 items. After the item deleted because factor loading was low, measured model was tested. The results of the measurement model indicated fit indices: $x^2$= 79.593(df = 38, 0 = 0.000), RMR = 0.045, GFI = 0.940, CFI = 0.904, AGFI = 0.896, NFI = 0.837, TLI = 0.861, RMSEA = 0.67. The squared correlation between four constructs were less than the average variance extracted(AVE) of four constructs. Multiple regression analysis was completed. Dependent variable was the perceived infection control practice by dental hygienist. Independent variables were four summated subscales(R = 0.552, $R^2$= 0.304, Adjusted $R^2$= 0.431, F = 25.813, p = 0.000). Unstandardized coefficients of three independent variables were statistically significant.

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A Study on Shape Optimization of Distributed Actuators using Time Domain Finite Element Method (시간유한요소법을 이용한 분포형 구동기의 형상최적화에 관한 연구)

  • Suk, Jin-Young;Kim, You-Dan
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.33 no.9
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    • pp.56-65
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    • 2005
  • A dynamic analysis method that freezes a time domain by discretization and solves the spatial propagation equation has a unique feature that provides a degree of freedom on spatial domain compared with the space discretization or space-time discretization finite element method. Using this feature, the time finite element analysis can be effectively applied to optimize the spatial characteristics of distributed type actuators. In this research, the time domain finite element method was used to discretize the model. A state variable vector was used in the discretization to include arbitrary initial conditions. A performance index was proposed on spatial domain to consider both potential and vibrational energy, so that the resulting shape of the distributed actuator was optimized for dynamic control of the structure. It is assumed that the structure satisfies the final rest condition using the realizable control scheme although the initial disturbance can affect the system response. Both equations on states and costates were derived based on the selected performance index and structural model. Ricatti matrix differential equations on state and costate variables were derived by the reconfiguration of the sub-matrices and application of time/space boundary conditions, and finally optimal actuator distribution was obtained. Numerical simulation results validated the proposed actuator shape optimization scheme.

RF performance Analysis for Galileo Receiver Design (갈릴레오 수신기 설계를 위한 RF 성능 분석에 관한 연구)

  • Chang, Sang-Hyun;Lee, Il-Kyoo;Park, Dong-Pil;Lee, Sang-Wook
    • Journal of Satellite, Information and Communications
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    • v.5 no.1
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    • pp.58-62
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    • 2010
  • This paper presents the effects of RF performance parameters on the Galileo receiver design via simulation after reviewing the requirements of the Galileo receiver structure. At first, we considered the general requirements, structure and characteristics of the Galileo system. Then we designed the Galileo receiver focused on performance requirement of 16 dB C/N which is equal to 15 % Error Vector Magnitude(EVM) by using Advanced Design System(ADS) simulation program. In order to verify the function of Automatic Gain Control(AGC)), we measured the IF output power level by changing the input power level at the front - end of the receiver. We analyzed the performance degradation due to phase noise variations of Local Oscillator(LO) in the Galileo receiver through EVM when the minimum sensitivity level of -127 dBm is applied at the receiver. We also analyzed the performance degradation according to variable Analog-to-Digital Converter(ADC) bits within the Dynamic range, -92 ~ -139 dBm, which has been defined by gain range (-2.5 ~ +42.5 dB) in the AGC operation. The results clearly show that the performance of the Galileo receiver can be improved by increasing ADC bits and reducing Phase Noise of LO.