• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년 학술대회 논문집 정보 및 제어부문
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• pp.585-587
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• 2006

Generally, LPF(low pass filter) circuits are used for converting square wave to average value, but these are not used necessary for average value of square wave in real time because of time constant of LPF. This paper deals with acquiring method for average value of square wave in real tine in case of frequency of output voltage is fixed, waveform of output voltage is square wave and duty of output voltage is varied like as 1 quadrant or 4 quadrant chopper.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2019년도 추계 학술논문 발표대회
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• pp.81-82
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• 2019

In this study, the Proctor penetration resistance test value and the hardness value of the improved Durometer were compared and analyzed for the change in the FA replacement rate of the concrete using CGS fine aggregate. The results are summarized as follows. It is. 1) The Proctor penetration resistance test value and the hardness value of the improved Durometer showed a high correlation in the form of a curve. 2) About surface finish Super-resolution with the improved Durometer is considered to be useful when using about 50 HD and about 80 HD in the end to determine the surface finishing work time.

• 한국염색가공학회지
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• 제21권2호
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• pp.14-21
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• 2009

In this article, silk fabric was treated with silver nitrate ($AgNO_3$) as oxidizing agent, with conditions such as concentration, and treating time, and subsequently treated with reducing agents such as sodium boron hydride ($NaBH_4$) and sodium sulfide ($Na_2S$) to obtain cathodic coloration. After coloration of silk fabric, dyeing properties (K/S value), colorfastnesses such as wash, rubbing and light, and antibacterial activity property were examined. $AgNO_3$ treating time and reducing time did not influence K/S value, whereas the pH value at alkaline region showed a high K/S value of silk fabric. The cathodic colorations of silk fabric with both of reducing agents at $30^{\circ}C$ have excellent color fastnesses. Also the high antibacterial activities were obtained by the treatment with silver nitrate even at 1% of lower concentration.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권2호
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• pp.960-973
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• 2018

This paper presents design for error correcting algorithm of the time of flight (ToF) detection value in the light detection and ranging (LIDAR) system sensor. The walk error of ToF value is generated by change of the received signal power depending on distance between the LIDAR sensor and object. The proposed method efficiently compensates the ToF value error by the independent ToF value calculation from the received signal using both rising point and falling point. A constant error of ~0.05 m is obtained after the walk error correction while an increasing error up to ~1 m is obtained with conventional method.

• 대한산업공학회지
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• 제24권1호
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• pp.51-59
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• 1998

This paper presents a new present value measure, the dynamic present value, or DPV. DPV takes into account not only the value of the realized cash flow but also that of potential cash flow. The DPV approach enables the analyst to observe differences in the present value of the alternatives every period over the whole time period of interest. This is the most fundamental advantage of the DPV approach over the traditional present value approach in which the present value of the alternatives is evaluated only one particular point of time. The concepts of the realized and potential cash flows are also developed in this paper. These new concepts are found to be useful elements in evaluating economic alternatives.

• Communications for Statistical Applications and Methods
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• 제11권1호
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• pp.107-120
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• 2004

The purposes of this study are to analyze economic value of science technology information for each distribution center First, the total economic value of each distribution center based on the value of time can be estimated to be 714,384,529 won, which can be compared with that of KISTI's 85,674,153,126 won. Second, the total economic value of each distribution center based on addition time can be estimated to be 1,426,344,558,446 won. And KISTI's 173,915,322,076 won appears to be the highest one as a single unit. Third, the study results can provide an objective standard for the policies of KISTI based on the data collected in this study.

• 대한가정학회지
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• 제18권4호
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• pp.87-94
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• 1980

This study was carried out to make a comparison between iced and partial freezing of bastard, yellow tail, poragy, pomfret that were generally used for Sashimi and the results that measured k-value, VB-N, TMA-N were measured and the results are as follows : 1. Regardless of the kinds of fish, freshness is better preserved in partial freezing than in iced storage. 2. In Bastard, Yellow tail When iced its freshness estimation index its K-value rose above 20% after 4 days of storage. When stored partially frozen, its K-value reached 20% after 8 days. 3. Porgy when iced, its K-value reach 20% after 6 days of storage. But when stored partially frozen, its K-value could be prolonged until 9 days with same degree. Porge was preserved for the longest time among the four fishes. 4. Pomfret When iced during 4 days and stored partially frozen during 6 days, their K-value reached about 20% Pomfret was preserved for the shortest time among the four fishes. 5. According to the kinds of fish, the results that measured VB-N, TMA-N, total bacteria have some differences, but the method of partial freezing was superior to iced storage.

• 대한치과보철학회지
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• 제45권2호
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• pp.250-262
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• 2007

Statement of problem: It was reported high success rate of implant-supported fixed prostheses using with $5{\sim}6$ implants on anterior mandible. Recently, immediate loading protocol was focused to overcome disadvantages of classic 2-stage delayed loading protocol. Purpose: This clinical study was to evaluate stability changes with time of immediately loaded and delayed loaded implants in edentulous mandible and to compare stability changes with time according to implantation sites. Materials and methods: Five or six implants were placed on anterior mandible depending on the arch shape. The immediately loading group was consisted of 8 patients received their prostheses within $24{\sim}48$ hours after implantation. The delayed loading group was consisted of 8 patients received their definitive prostheses following classical prosthetic procedures after a healing period of 3 months. All patients were recalled every 6 months for check-up. The evaluations of radiographic examination, ISQ value measurement and recording of complication were done. To evaluate marginal bone level, intraoral periapical radiographs were taken with long cone paralleling technique. At every evaluation recall, all prostheses were removed and ISQ values were measured with OsstellTM on individual implants. Results: 1. None of implants was failed. All implants showed stable marginal bone levels and ISQ values. 2. Marginal bone level changes with time showed statistically significant difference between immediately loading group and delayed loading group (P<0.001). 3. ISQ value changes with time did not show statistically significant difference between immediately loading group and delayed loading group (P=0.079). ISQ value decreased with time in both groups, however, all implants showed stable ISQ value at 30 months-recall evaluation. 4. Marginal bone level changes with time did not show statistically significant differences among implantation sites (P=0.604). 5. ISQ value changes with time showed statistically significant differences among implantation sites (P=0.047). ISQ values of most posterior implants decreased with time comparing to other implants. Conclusion: Although the marginal bone level of the terminal abutment didn't different with the other implants, ISQ value of the terminal abutment was lower than that of the other implants. Therefore, further clinical evaluation would be needed in this point of view.

• 한국정밀공학회지
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• 제12권5호
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• pp.57-68
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• 1995

A general procedure for the numerical solution of coupled, nonlinear, differential two-point boundary-value problems, solutions of which are crucial to the controller design, has been developed and demonstrated. A fixed-end-points, free-terminal-time, optimal-control problem, which is derived from Pontryagin's Maximum Principle, is solved by an extension of Davidenko's method, a differential form of Newton's method, for algebraic root finding. By a discretization process like finite differences, the differential equations are converted to a nonlinear algebraic system. Davidenko's method reconverts this into a pseudo-time-dependent set of implicitly coupled ODEs suitable for solution by modern, high-performance solvers. Another important advantage of Davidenko's method related to the time-optimal problem is that the terminal time can be computed by treating this unkown as an additional variable and sup- plying the Hamiltonian at the terminal time as an additional equation. Davidenko's method uas used to produce optimal trajectories of a single-degree-of-freedom problem. This numerical method provides switching times for open-loop control, minimized terminal time and optimal input torque sequences. This numerical technique could easily be adapted to the multi-point boundary-value problems.

• 한국데이타베이스학회:학술대회논문집
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• 한국데이타베이스학회 2010년도 춘계국제학술대회
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• pp.203-212
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• 2010

The mam purpose of this study is to find out how perceived risk elements influence to customers' perceived value and repurchase intention in the electronic commerce environment. To achieve the goal, we set 6 sub-dimensions - privacy risk, social risk, time loss risk, economic risk, psychological risk, and performance risk - based on comprehensive consideration of related studies, and established a research model included 2 factors such as perceived value and repurchase intention to measure performance in internet shopping malls. From 174 customers of the electronic commerce shopping malls survey data have been collected and analyzed based on the covariance structural model method. The results of this study are summarized as follows. Firstly, five perceived risk characteristics of privacy risk, time loss risk, economic risk, psychological risk, and performance risk are significantly positive effect on perceived value. Secondly, perceived value IS very significantly related to repurchase intention in electronic commerce shopping malls. Consequently, we discussed the strategies to create perceived value and repurchase intention in electronic commerce environment. Also we suggested the implications and further research directions.