• The Transactions of the Korean Institute of Electrical Engineers A
• /
• v.52 no.12
• /
• pp.698-704
• /
• 2003

Autoreclosure provides a mean of improving power transmitting ability and system stability. The conventional reclosure adopts the fixed dead time interval strategy, that is, the reclosure is activated after a time delay to restore the system to normal as quickly as possible without regard to the system conditions, however, these simple techniques cannot give the optimal operating performance. For this reason, various adaptive reclosure algorithms have been proposed recently, This paper presents an adaptive autoreclosure algorithm including the variable dead time, optimal reclosure, sequential reclosure and emergency extended equal-area criterion (EEAC) algorithm in order to improve the system stability. The reclosure algorithm performs out the operations that are attuned to the power system conditions. The proposed adaptive reclosure algorithm is verified and tested by using EMTP MODELS, and the simulation results show that the system oscillations are reduced and the transient stability is enhanced by employing the proposed adaptive reclosure algorithm.

• Proceedings of the PSK Conference
• /
• 2003.10b
• /
• pp.90.3-91
• /
• 2003

The most commonly proposed mechanism for QT interval prolongation(LQT) by pharmaceuticals is inhibition of the rapid delayed rectifier potassium channel (I$\_$Kr/). The LQT potency of pharmaceuticals can be effectively evaluated by examining the effect on hERG channels expressed in CHO cells, known to be equal to I$\_$Kr/. But, It was known that hERG channels according to increase the bath temperature have several changes, including a marked increase in the amplitude of the outward and tail currents, and acceleration of the rates of activation, recovery from inactivation, and deactivation. (omitted)

• Asian-Australasian Journal of Animal Sciences
• /
• v.27 no.1
• /
• pp.83-92
• /
• 2014

This experiment was conducted to evaluate the effects of dietary CP levels in gestation under equal lysine content on reproductive performance, blood metabolites and milk composition of gilts. A total of 25 gilts ($F_1$, Yorkshire${\times}$Landrace) were allotted to 4 dietary treatments at breeding in a completely randomized design, and fed 1 of 4 experimental diets containing different CP levels (11%, 13%, 15%, or 17%) at 2.0 kg/d throughout the gestation. Body weight of gilts at 24 h postpartum tended to increase linearly (p = 0.09) as dietary CP level increased. In lactation, backfat thickness, ADFI, litter size and weaning to estrus interval (WEI) did not differ among dietary treatments. There were linear increases in litter and piglet weight at 21 d of lactation (p<0.05) and weight gain of litter (p<0.01) and piglet (p<0.05) throughout the lactation as dietary CP level increased. Plasma urea nitrogen levels of gilts in gestation and at 24 h postpartum were linearly elevated as dietary CP level increased (p<0.05). Free fatty acid (FFA) levels in plasma of gestating gilts increased as dietary CP level increased up to 15%, and then decreased with quadratic effects (15 d, p<0.01; 90 d, p<0.05), and a quadratic trend (70 d, p = 0.06). There were no differences in plasma FFA, glucose levels and milk composition in lactation. These results indicate that increasing dietary CP level under equal lysine content in gestation increases BW of gilts and litter performance but does not affect litter size and milk composition. Feeding over 13% CP diet for gestating gilts could be recommended to improve litter growth.

• Journal of the Korean Operations Research and Management Science Society
• /
• v.3 no.1
• /
• pp.31-46
• /
• 1978

Consider a time interval during which the demand for trips is fixed (e.g. the rush hour period). The traveller has a choice between various public modes, whose travel times and fares are fixed, and the automobile mode, for which travel time and cost depend on the volume of traffic flow on those roads, which are subject to congestion. We consider the equilibrium in terms of a representative travellerm, who choses for any trip the mode and route with the least combined money and time cost. When several (parallel) model or routes are chosen, then the combined cost of money and time must be equal among these. Our problem is first, to find the optimal flows of cars and of public mode carriers on the various links of their networks and second the optimal fares for trips by the variousmodes. The object is to minimize the total operating costs of the carriers and car plus the total time costs to travellers. The optimal fares are related to, but not identical with the dual variables of the underlying Nonlinear Program. They are equal to these dual variables only in the case, when congestion tolls on trips or on the use of specific roads are collected from automobile users. When such tolls are not collected, they must be passed on as subsidies to travellers using competing modes. The optimal fares of public modes are then reduced by the amounts of these subsidies. Note that subsidies are not a flat payment to public carriers, but are calculated on the basis of tickets sold. Fares and subsidies depend in general on tile period considered. They will be higher during periods of higher demand. When the assumption of fixed trip demand is relaxed, this tare system is no longer best, but only second best since too much traffic will, in general, be generated. The Free Rider Theorem states the following : Suppose road tolls can be charged, so that a best pricing system for public modes is posssible. Then there may exist free rides on some routes and modes, but never on a complete round trip.

• Journal of the Society of Disaster Information
• /
• v.17 no.2
• /
• pp.319-328
• /
• 2021

Purpose: Recently, a large social disaster has called for the need to diagnose social disaster safety, and the Ministry of Public Administration and Security calculates and publishes regional safety ratings such as regional safety index and national safety diagnosis every year. The existing safety diagnosis system uses equal intervals or normal distribution to grade risk maps in a uniform manner. Method: However, the equidistant technique can objectively analyze risk ratings, but there is a limit to classifying risk ratings when the distribution is skewed to one side, and the z-score technique has a problem of losing credibility if the population does not follow a normal distribution. Because the distribution of statistical data varies from indicator to indicator, the most appropriate rating should be applied for each data distribution. Result: Therefore, in this paper, we analyze the data of disaster indicators and present a comparison and suitable method for traditional equidistant and natural brake techniques to proceed with optimized grading for each indicator. Conclusion: As a result, three of the six new indicators were applied differently from conventional grading techniques

• Geophysics and Geophysical Exploration
• /
• v.6 no.4
• /
• pp.171-179
• /
• 2003

In land and marine seismic survey, we generally set receivers with equal interval suppose that sampling interval Is too narrow. But the cost of seismic data acquisition and that of data processing are much higher, therefore we should design proper receiver interval. Spatial aliasing can be occurred on seismic data when sampling interval is too coarse. If we Process spatial aliasing data, we can not obtain a good imaging result. Trace interpolation is used to improve the quality of multichannel seismic data processing. In this study, we applied the Spitz algorithm which is widely used in seismic data processing. This algorithm works well regardless of dip information of the complex underground structure. Using prediction filter and original traces with linear event we interpolated in f-x domain. We confirm our algorithm by examining for some synthetic data and marine data. After interpolation, we could find that receiver intervals get more narrow and the number of receiver is increased. We also could see that continuity of traces is more linear than before Applying this interpolation algorithm on seismic data with spatial aliasing, we may obtain a better migration imaging.

• The Journal of Engineering Geology
• /
• v.30 no.4
• /
• pp.515-523
• /
• 2020

If the safety factor does not secure the safety factor suggested in the design standard at the slope design stage, the safety factor is secured by installing an anchor. Stability analysis is used to verify the effect of reinforcing the slope of the anchor, but in this process, most of the anchor construction intervals are assumed to be equal and analyzed. For economical and effective slope reinforcement, stability analysis is required by adjusting the anchor construction interval. In this study, the effect of the anchor construction interval on the change of the safety factor of the slope was identified. Stability analysis was performed by setting a virtual slope with two berms and different anchor construction intervals. As a result of the analysis, the stability of the slope is secured when the anchor spacing of the lower surface is narrowed and the anchor gaps of the upper and middle surfaces are wider than when anchors are installed at the same intervals on the upper, middle, and lower surfaces of the slope. The result was a 15% reduction in the amount of anchors. This means that, rather than reinforcing anchors at the same intervals, it is economical and effective to have an economical and effective reinforcement effect to vary the anchor construction intervals according to the slope characteristics.

• Asian-Australasian Journal of Animal Sciences
• /
• v.5 no.3
• /
• pp.427-433
• /
• 1992

Reproduction and growth to weaning were compared for Brahman crossbred (BX) and a local strain of South-East Asian cattle, "Javanese Zebu" (JZ) and their reciprocal crosses at "Erap" in the humid equatorial lowlands of Papua New Guinea. Forty heifers of each breed were mated continuously, half to bulls of each breed, for five years. BX calved first at 35 months while JZ calved at 31 months. Subsequent calving intervals were very short, at 370 and 341 days. JZ cows weighed about two thirds of the BX cattle at each stage of reproduction. Birth weights and growth to weaning were : BX 35 kg and 0.68 kg/d ; BX male $\times$ JZ female 29.3 kg and 0.53 kg/d ; JZ male $\times$ BX female 30.8 kg and 0.61 kg/d ; JZ 25 kg and 0.50 kg/d. The combination of small cow size, short calving interval and rapid calf growth resulted in the BX male $\times$ JZ female being the most efficient producer, in kg of calf weaned per cow mated per year while the reciprocal cross was the least efficient ; both straight-breds were equal and intermediate. These data show that indigenous equatorial cattle may not be inferior under good grazing conditions. For all traits, breed interactions (heterosis) was small and non-significant.

• Journal of Animal Reproduction and Biotechnology
• /
• v.35 no.3
• /
• pp.279-288
• /
• 2020

Changes of gonadal morphology and mRNA expression patterns of vitellogenin were investigated in Siberian sturgeon Acipenser baerii (Chondrostei) during its early gonadal maturation period. Early differentiations and morphological transitions of both ovaries and testes appeared to occur actively until the age of 3 years, however from then on, the maturation patterns to full maturity were largely gender-dependent, in which males showed a faster progression of maturation than did females while females experienced a steady-state progress with a lagged interval before entering the final maturation. Expression of vitellogenin mRNAs are closely correlated with transitional patterns of gonadal appearances. In both females and males, hepatic mRNA levels of vitellogenin exponentially increased in the earliest interval (up to 1-year-old). However, in subsequent periods, vitellogenin expression in females continued to increase with age, whereas in males, the expression stabilized at a younger age. Nevertheless, at the age older than or equal to 7-year-old, fully matured individuals showed a quite low level of vitellogenin expression in both females and males. Collectively, results from this study could be useful as a fundamental guideline to address the gonad maturation of this sturgeon species, which is helpful for making practical decisions about farming practices and management for caviar production on local sturgeon farms.

• Journal of the Korean Geographical Society
• /
• v.36 no.4
• /
• pp.434-443
• /
• 2001

Differing from the existing method to optimize the statistical proximity, the new optimization method was developed to maximize the spatial proximity among the unit areas of choropleth map. 25 choropleth maps were made using 5 classification methods(maximum BEI, maximum TEI, equal interval, natural break, n-tile) for 5 classes(3∼7) and were analyzed to elucidate the effectiveness of classification methods on the basis of 3 evaluation indeces (TEI, BEI, $C_{F}$). The results from the maximum TEI and maximum BEI were evaluated as relatively stable and effective compared to those from other classification methods. But they showed the opposite trends owing to the trade-off relationships. Meanwhile, the resets from the natural break method got higher marks, which was also identified through the analysis using a new $alpha$-index.x.