• 반도체디스플레이기술학회지
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• 제3권1호
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• pp.35-39
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• 2004

Statistical design of experiments was successfully employed to investigate the effect of alternating magnetic field on activation of polycrystalline Si (p-Si) doped as n-type using $\textrm{PH}_3$, by full factorial design of three factors with two levels. In this design, the input variables are graphite size, alternating current, and activation time. The output parameter, sheet resistance, is analyzed in terms of the primary effects and multi-factor interactions. Notably, the three-factor interaction is calculated to be a dominant interaction. The interaction between graphite size and activation time and the main effect of current are important effects compared to the other variables and relevant interactions. Alternating magnetic flux activation is proved a significantly beneficial processing technique.

• 한국경영과학회지
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• 제25권1호
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• pp.1-13
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• 2000

Electronic Data Interchange (EDI) has a significant impact on business practices by eliminating paper related adult trails and enabling transactions to be processed at high speed without human intervention. Major advantages advangtages and benefits derived from EDI, however, depend upon the usage of EDI controls. Management must determine whether their investment on EDI controls is appropriate, as the establishment of EDI controls demandds much resources and high skills. This study proposes data envelopment analysis model to identify efficient and inefficient EDI control systems in various context of input (formal and automated EDI controls) and output (EDI implementation and performance). DEA can also determine the factors that are significantly different between efficient and inefficient groups. The model is tested using data collected form EDI adopters.

• 대한안전경영과학회지
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• 제12권4호
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• pp.191-198
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• 2010

This paper selects length of berth, area of yard, unloading capacity and number of berth as the input indexes, and cargo turnover as output index to research the source of turnover growth of 22 main ports in Korea. We gains the following results: in general, the trade ports in Korea are the stage of expansion period, the sources of turnover growth depends on the growth of factor inputs and could not be supported by TFP and technical progress. Especially in the west and east coast, TFP and technical progress is the block to the turnover growth. Four major factors to the increase of TFP are following: competition between ports, reform of property system, harbor-hinterland economic and international trade, modeling, imitation and innovation in management, technology and system.

• 영어어문교육
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• 제13권2호
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• pp.1-23
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• 2007

The purpose of this research is to explore the effects of systematic teaching English pronunciation and listening in English. Focusing on phonemes and words in pairs and sentences, the sound systems of the English and Korean languages are dealt with in conjunction with the test data. This paper first discusses the systemic, or primary interference and the habitual, or secondary interference that hinder comprehension of certain English sounds. Second, the analysis of input and output test data on the contrasting vowels and consonants shows statistic significance in terms of the probability (p value) of t-test. Third, the comparative data by means of percentile of right answers on contrasting vowel and consonant sounds expound the different sound systems of the English and Korean languages. With this data, problems in pronunciation of and listening to English, and the factors that may cause these problems are analyzed so that they can be used as a guideline for a systematic approach in teaching English learners, thus leading to more satisfactory performance.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1998년도 가을 학술발표대회 논문집(III)
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• pp.656-661
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• 1998

This paper presents a method of statistical analysis and sensitivity analysis of creep and shrinkage effects in PSC box girder bridges. The statistical and sensitivity analyses are performed by using the numerical simulation of Latin Hypercube sampling. For each sample, the time-dependent structural analysis is performed to produce response data, which are then statistically analyzed. The probabilistic prediction of the confidence limits on long-term effects of creep and shrinkage is then expressed. Three measures are examined to quantify the sensitivity of the outputs to each of the input variables. These are rank correlation coefficient(RCC), partial rank correlation coefficient(PRCC) and standardized rank regression coefficient(SRRC) computed on the ranks of the observations. Probability band widens with time, which indicates an increase of prediction uncertainty with time. The creep model uncertainty factor and the relative humidity appear as the most dominant factors with regard to the model output uncertainty.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1999년도 춘계학술대회 논문집
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• pp.630-633
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• 1999

This paper presents a new sort of multilayer piezoelectric ceramice transformer for switching regulatied power supplies. And this paper presents the study and development of a DC-DC converter with a transformer made from piezoelectric materials. This piezoelectric transformer operate, in the second thickness extensional vibration mode. Its resonant frequency is higher than 1MHz, This piezoelectric transformer was used the PbTiO$_3$ family ceramics because it was a material large anisotropy between electromechanical coupling factors k$_{t}$ and k$_{p}$. The input and output layer consists of two piezoelectric ceramic layer for eleivater of outpur power.wer.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 D
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• pp.2651-2654
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• 2000

In this paper, we re-analyzed the fuzzy controller as conventional PID controller structure, and proposed a self tuning fuzzy PID controller whose input output scaling factors were tuned automatically. At first stage, the tuning parameters of fuzzy controller were determined by Ziegler-Nichols tuning method and then they were adjusted as the delay time and process environment were changed. Proposed controller was simple in its structrue and computational burden was small so that on line adaptation was easy to apply to. The result of computer simulation and practical experiment showed the proposed controller's excellent performance

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 B
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• pp.682-684
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• 1995

The most effective way to improve the performance of a fuzzy controller may be to optimize look-up values. Look-up values are derived from processes used input-output scale factors, membership functions, rule base, fuzzy inference method and defuzzification. It is powerful way to modify or organize look-up table values. In this paper, We propose the look-up values self-organizing fuzzy controller(LSOFC). We use the plus-minus tuning method(PMTM), scanning values through the processes of addition and subtraction. We show the efficiency of this LSOFC by the results of simulation for nonlinear time-varying plant with unmodelled dynamics.

• 대한산업공학회지
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• 제26권4호
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• pp.402-410
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• 2000

The current study examines principles to develop universal design guidelines for manufacturing information and communication devices. The study surveyed inconveniences disabled people experience in the information and communication environment with current technology and design, and suggested abbreviated universal design guidelines. Design guidelines should reduce those inconveniences detected through the task analysis and GOMS modelling of the usage by disabled people. Design and functional features of mobile phones were examined since they quickly became essential communication tools for both disabled and non-disabled people alike. Design issues were examined in controls, input methods, and output methods in terms of human factors and ergonomics. It is expected that both governments and manufacturers can save costs to produce and manufacture special assistive devices for disabled people by implementing universal design in their communication products. Since it is becoming the international trend, application of the universal design should be enforced to all communication and information devices by government for the higher quality of life for all groups of user.

• 산업공학
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• 제7권3호
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• pp.171-180
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• 1994

Defined is a Multi-level Parallel Machine Flow-Shop (MPMFS) which reflects some real world manufacturing situations. Just-In-Time (JIT) philosophy is applied to the MPMFS scheduling in order to achieve lowering work-in-process inventory level as well as meeting due dates. A schedule generating simulator is developed. The latest start time of each operation is determined by a backward simulation followed by another forward simulation to analyze the schedule feasibility and actual inventory level. Reasonable schedules are available through adjusting some parameters for allowance factors such as set-up times of machines and other environmental changes. The SLAMSYSTEM under Window is employed for this processing with some input/output data handling processes devised under DOS.