• 대한전자공학회논문지
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• 제26권11호
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• pp.1666-1671
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• 1989

A novel switched-capacitor circuit for interfacing capacitive microtransducers with a digital system is developed based on the dual-slope integration. It consists of a differential integrator and a comparator. Driven by the teo phase clock, the circuit first senses the capacitance difference between the transducer and the reference capacitor in the form of charge, and accumulates it into the feedback capabitor of the integrator for a fixed period of time. The resulant accumulated charge is next extracted by the known reference charge until the integrator output voltage refurns to zero. The length of time required for the integrator output to return to zero, as measured by the number of clock cycle gated into a counter is proportional to the capacitance difference, averaged over the integration period. The whole operation is insensitive to the reference voltage and the capacitor values involved in the circuit, Thus the proposed circuit permits an accurate differental capacitance measurement. An error analysis has showh that the resolution as high as 8 bits can be expected by realizing the circuit in a monolithic MOS IC form. Besides the accuracy, it features the small device count integrable onto a small chip area. The circuit is thus particularly suitadble for the on-chip interface.

• 대한치과교정학회지
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• 제42권5호
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• pp.255-262
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• 2012

Objective: We aimed to compare the retention characteristics of Essix and Hawley retainers. Methods: Adolescents undergoing fixed appliance treatment at 2 centers were recruited for this study. Twenty-two patients (16 women and 6 men) wore Essix retainers (Essix group) while 20 (14 women and 6 men) wore Hawley retainers (Hawley group). The mean retention time was 1 year, and the mean follow-up recall time for both groups was 2 years. Two qualified dental examiners evaluated the blind patient data. Maxillary and mandibular dental casts and lateral cephalograms were analyzed at 4 stages: pretreatment (T1), post-treatment (T2), post-retention (T3), and follow-up (T4). Results: The results revealed that Essix appliances were more efficient in retaining the anterior teeth in the mandible during a 1-year retention period. The irregularity index increased in both arches in both groups after a 2-year post-retention period. The mandibular arch lengths increased during treatment and tended to return to their original value after retention in both groups; however, these changes were statistically significant only in the Hawley group. Cephalometric variables did not show any significant differences. Conclusions: The retention characteristics of both Essix and Hawley retainers are similar.

• 수산경영론집
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• 제28권1호
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• pp.85-117
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• 1997

This paper is focused on management control system. From a management control perspective, strategies should be viewed as useful, but not absolutely necessary, guides to the proper design of an MCS. When strategies are formulated more clearly, more control alternatives become feasible and it becomes easier to implement each form of management control effectively. The common and important category of controls are action controls, personnel and cultural controls, and results controls. Action controls involves ensuring that employees perform(or do not perform) certain actions that are known to be beneficial(or harmful) to the organization. Personnel and cultural controls take steps to ensure that employees will control each others' behaviors. Results controls involve rewarding individuals(and sometimes groups of individuals) for generating good outcomes or punishing them for poor outcomes. The results controls of ROI-type measure cause to make managers excessively short- term oriented, or myopic. When managers' orientations to the short - term become excessive -when the management are more concerned with short-term profit than entity value-the managers are said to be myopic. We car, solve myopic problem by introducing AR(abnormal return), near-perfect indicators of value creation. The results - control ideal would be to hold all employees accountable for the wealth they individually create(or destroy) for the owners of the entities in which they work. This ideal is approachable for top management of publicly traded corporations because for these organizations, the wealth created(returns to shareholders) can be measured directly for any period(such as a year, a quarter, or a month) as the measurement period pin(or minus) the change in the market value of the stock.

• 천문학회보
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• 제35권1호
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• pp.87.2-87.2
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• 2010

Near-Earth asteroid-comet transition object 4015 Wilson-Harrington is a possible target of the joint European Space Agency (ESA) and Japanese Aerospace Exploration Agency (JAXA) Marco Polo sample return mission. 4015 W-H was discovered showing cometary activity by Albert G. Wilson and Robert G. Harrington at Palomar Observatory in 1949. After recovered in 1979, 4015 W-H has been observed at every apparition, it always was seen as a point source. We made time series observations for 4015 W-H using the 1.8m telescope with 2K CCD at Bohyunsan Observatory, on the nights of 2009 November 17-19. The geocentric distance of 4015 H-W was about 0.38 AU at that time. No trace of cometary activity is seen from our images. From the light curve analysis, we find a double-peaked rotational period of 2.2 hours with amplitude of 0.4 magnitude. Our result is much shorter than previous measurements of 3.6 hours (Harris & Young 1983) and 6.1 hours (Osip et al 1995). We will discuss possible origin of the period variations.

• Asian-Australasian Journal of Animal Sciences
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• 제4권1호
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• pp.85-90
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• 1991

Weaner heifers were set stocked at 4/ha on a grass-legume pasture in South Sulawesi, Indonesia, and either unsupplemented (Control) or for 338 days given daily supplements of one of, rice bran (RB) supplied at 1 kg/animal/d, molasses/urea (MU) or 0.5 RB + 0.5 MU (MURB) the amounts of which were adjusted to give similar energy intakes. There were 20 animals in each treatment. A drought resulted in low pasture availability for about half the supplementation period. The LWG per animal in the MURB treatment was 85 kg above that of the control and this was significantly greater (p < 0.01) than those for MU (62.0 kg) or RB (56.2 kg) although the economics favoured the gains from RB which returned over three times the cost of the supplement. Costs could be reduced by supplementing only at times of maximum undernutrition, but such a strategy is of doubtful value in this situation as there was no compensatory LWG and a similar rate of economic return was maintained throughout the period. The results suggest that additional benefits from the supplementation may be improved reproductive performance and more efficient use of pasture.

• The Journal of Asian Finance, Economics and Business
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• 제7권7호
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• pp.15-25
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• 2020

This empirical research aims to identify the relationship between fiscal and financial macroeconomic fundamentals and the volatility of government bonds' borrowing cost in an emerging country - Vietnam. The study covers the period from July 2006 to December 2019 and it is based on a sample of 1-year, 3-year, and 5-year government bonds, which represent short-term, medium-term and long-term sovereign bonds in Vietnam, respectively. The Generalized AutoRegressive Conditional Heteroskedasticity (GARCH) model and its derivatives such as EGARCH and TGARCH are applied on monthly dataset to examine and suggest a significant effect of fiscal and financial determinants of bond yield volatility. The findings of this study indicate that the variation of Vietnam government bond yields is in compliance with the theories of term structure of interest rate. The results also show that a proportion of the variation in the yields on Vietnam government bonds is attributed to the interest rate itself in the previous period, base rate, foreign interest rate, return of the stock market, fiscal deficit, public debt, and current account balance. Our results could be helpful in the macroeconomic policy formulation for policy-makers and in the investment practice for investors regarding the prediction of bond yield volatility.

• 대한수의학회지
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• 제14권1호
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• pp.29-31
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• 1974

The total serum protein, protein fractions by paper electrophoresis and A/G ratio in pregnant rabbits were observed. The results obtained in this work were sumrnerized as follows: 1. Total serum protein and the fraction of serum albumin revealed a decrease with the advancing of gestation, especially total serum protein was decreased significantly on 3 weeks of pregnancy. There was a tendency to return tward control level on one week after delivery. 2. The fraction of ${\alpha}_1$, and ${\alpha}_2$-globulin showed little changes during the period of gestation. 3. The fraction of ${\beta}$-globulin was increased more or less during the period of gestation, and on one week after delivery showed considerable increase but the increase was statistically insignificant. 4. The fraction of ${\gamma}$-globulin revealed a variable changes during pregnancy but there was no significant differences. 5. A/G ratio was significantly decreased at 3 weeks of pregnancy and the ratio was near control level on one week after delivery.

• 농촌계획
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• 제24권3호
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• pp.55-62
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• 2018

This study analyze factors influencing business performance by types of agricultural corporation for improving performance. The number of agricultural corporations have been increasing but their profitability has been decreasing. In this situation, it is important to analyze factors influencing business performance for improving their profitability. We estimate a model including financial indexes and corporation's characters using ordinary least square. We use agricultural corporations survey data for 10years(2005~2014) of Statistics Korea. This study analyze bookkeeping recorded agricultural corporations for the same period. As a result, we find factors to influence Return on Assets(ROA). Additionally, we calculate optimized current ratio and debt ratio for ROA maximization. Operation period and the number of full-time workers also have a positive effect on ROA. Agricultural production, processing and distribution variables by business types have a positive effect on ROA, but some of their interaction terms have a negative effect on ROA. We expect that this result will help for improving corporation's business performance.

• 설비공학논문집
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• 제19권12호
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• pp.857-864
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• 2007

In the current residential building, hot water supply system consumes the second largest energy in order to make the thermal comport condition of residential space. The more residential environment improves the more the demand for hot water and water consumption is increasing gradually. So this study examines the possibility of applying the recirculation for individual hot water supply system compared with the existing method for waiting time for hot water, wasted water and energy consumption. The results are as follows. (1) In case of recirculation system method the waiting time for hot water can be reduced up to $69\sim85%$ in spring and fall period and so dose up to $77\sim85%$ in winter period. (2) The total wasted water has a little change compared with the existing method which can make the total wasted water reduced about $77\sim86%$. (3) The efficiency of hot water supply system can be improved, if the method which blocks the inflow of cold water is applied, when return pump is operated to recirculate hot water in recirculation system.

• 물과 미래
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• 제23권4호
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• pp.499-507
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• 1990

홍수기중의 실시간 저수지 운영을 위해서는 매시간 on-line으로 입력된 자료와 예측치로부터 시간별 최적방류량을 구해야 한다. 이를 위해서 댐하류의 홍수피해를 최소화하고 홍수 말기의 용수보존을 고려하는 무의 모형의 기법을 발표한 바 있다. 본 논문에서는 홍수시의 대청댐의 단일저수지 운영을 위해 모형을 적용하고 결과를 검토하며, 과거의 측정된 유입량과 방류량자료도 검토한다. 초기저수위를 달리하여 각 재현 기간별 홍수수문곡선을 다루고, 강우유출 모형으로부터 얻은 예측유입량을 구하여 운영한 뒤에 실제값과 비교하였다. 연구결과에 의하면 예측유입량의 불확실성을 고려하기 위해 위험계수를 적용하면 홍수조절용량을 효율적으로 이용할 수 있다.