• Journal of information and communication convergence engineering
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• 제7권2호
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• pp.185-192
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• 2009

In wireless mesh networks multi-rate technology environment, a mesh node can dynamically modify the data transmission rate on a particular link, in response to link distance, or more accurately, the perceived SNR ratio between neighbor nodes. In such networks, existing route selection schemes use a link quality metric. Thus, these schemes may easily result in the network being overloaded. In this paper, a new route metric is proposed; it considers both per-hop service delay and link quality at mesh nodes. In addition, the Load-Aware AODV (LA-AODV) protocol using the proposed metric is presented. The performance evaluation is performed by simulation using the OPNET simulator. It is demonstrated that the LA-AODV protocol outperforms the existing routing protocols using other existing route metrics in multi-rate WMN environment.

• 대한음성학회:학술대회논문집
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• 대한음성학회 2007년도 한국음성과학회 공동학술대회 발표논문집
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• pp.315-318
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• 2007

This paper proposes the methods to enhance the speech quality of source controlled variable bit-rate coder based on the waveform interpolation. The methods are to estimate and generate the parameters that are not transmitted from encoder to decoder by the repetition and extrapolation schemes. For the performance evaluation, the PESQ(Perceptual Evaluation of Speech Quality) scores are measured. The experimental results shows that our proposed method outperforms the conventional source controlled variable bit-rate coder. Especially, the performance of the extrapolation method is better than that of the repetition method.

• Journal of Communications and Networks
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• 제4권3호
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• pp.199-208
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• 2002

The downlink rate scheduling problem is considered for CDMA networks with multiple users carrying packets of heterogeneous traffic (voice/audio only, bursty data only or mixed traffic), with each type having its own distinct quality of service requirements. Several rate scheduling algorithms are developed, the common factor of which is that part of the decision on which users to serve is based on a function of the deadline of their head-ofline packets. An approach of Andrews et al., in which the basic Earliest-Deadline-First algorithm is studied for similar systems, is extended to result in better performance by considering a more efficient power usage and by allowing service of more than one user per timeslot if the power resources permit it. Finally, the performance of the proposed schemes is compared through simulations.

• International Journal of Quality Innovation
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• 제9권3호
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• pp.15-27
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• 2008

As a sign of international quality system, ISO9000 certification has been adopted by more and more enterprises. In recent five years, there have been 560,000 certified companies in Europe and America, and there have been more than 390,000 ones in China. It has being attracted many quality scholars' attentions whether ISO9000 certification can bring more benefits to certified companies or not. This paper investigates the ISO9000 certification effect on market performance by the samples from Chinese list companies in shanghai stock exchange. Considering ISO9000 certification as an event, a certification effect model will be set up by means of the event study method, which takes abnormal return rate as a basic indicator to measure the ISO9000 certification effect on Chinese market performance in different event times. Investigation results show that the Chinese certified companies have some positive effects on market performance in the short term. From a long standpoint, the relation between certification and performance has a positive trend.

• Asian-Australasian Journal of Animal Sciences
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• 제26권2호
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• pp.211-217
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• 2013

A herd of polish lowland local sheep was divided into two equal groups: the first group was kept under an overhead shelter, and the second group was kept in a warm barn. The effect of maintenance on ewe's reproductive performance, survival as well as the growth rate of lambs, and their carcasses quality was investigated. The lack of differences in fertility and prolificacy of ewes as well as in the survival and growth rate between the groups confirmed a good adaptation of $\dot{Z}$ela$\acute{z}$nie$\acute{n}$ska sheep to low temperature. Harsh environmental conditions did not cause a significant decrease of the body weight growth; however, they brought in an (insignificant) reduction of subcutaneous fat thickness and meatiness of the loin part of a lamb's body. The fat content of carcasses obtained from lambs reared under the overhead shelter was significantly lower, with no differences of meat and bones contribution between the groups.

• International Journal of Quality Innovation
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• 제10권1호
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• pp.115-126
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• 2009

Video transmission effectiveness in the Ad Hoc network is becoming important recently, if different routing protocols are applied. Some researchers conclude that the reactive protocols are better for file transfer protocol (FTP) and constant bit rate (CBR) or hypertext transfer protocol (HTTP) transmission in an Ad Hoc wireless network but the performance report of video transmission is not much. This study adopts Qualnet (Network Simulator) as a simulation tool for environmental designing and performance testing, and employs an experimental design with eight groups. Our experiment shows that: (1) The performance of AODV (reactive) protocol is better than DSDV, ZRP and DSR when the transmission load has only one video stream; (2) Proactive (DSDV) and Hybrid protocols (ZRP) are better for a smaller Ad Hoc network when it transmits a video stream with some applications (VoIP, FTP and CBR). We conclude that packet loss rate is sensitive to the quality of video transmission and it has negative relationship with Peak Signal-to-Noise Ratio (PSNR) value. In addition, our experiment also shows that PSNR is a simple Metric for the performance evaluation of video transmission.

• 품질경영학회지
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• 제25권3호
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• pp.51-61
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• 1997

We introduce a method of estimating an unknown failure rate function based on sample data. We estimate failure rate function by a function s from a space of cubic splines constrained to be linear (or constant) in tails using maximum likelihood estimation. The number of knots are determined by Bayesian Information Criterion(BIC). Examples using simulated data are used to illustrate the performance of this method.

• Journal of Construction Engineering and Project Management
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• 제2권2호
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• pp.1-17
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• 2012

The automated construction machines have been recently developed to help solve the construction industry problems that significantly affect labour, productivity, quality, and profit. Despite the importance of performance analysis to commercialize the automated construction machines, previous studies have mainly concentrated on developing hardware and software of automated construction machines. This research now focuses on two objectives: (1) to propose an analysis model which can measure productivity, quality, and safety improvement rate of automated construction machines based on research and development (R&D); and (2) to develop a performance analysis system which will aid the evaluator in analysing the performance of automated construction machines. Finally, it is anticipated that the effective use of the performance analysis model and computerized system will ably develop the high-performance, automated construction machines and establish the marketing strategy to increase not only the commercial value but also the upkeep and development of construction machines.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 1997년도 학술대회
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• pp.181-186
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• 1997

Transcoding is the key technique to further reduce the bit-rate of a previously compressed video. The performance of the transcoding is evaluated by the two factors, the accuracy on the target bit-rate and the complexity of the implementation. In this paper, were propose a new rate control algorithm which has very accurate bit-rate control performance and much smaller computational complexity. For the accuracy problem, we empirically observe the relationship between the quantization step size and generated bits in requantization process and then find that the relationship can be characterized as the new piece-wise linear model. For the complexity problem, we reduce the role of feedback rate control. The simulation results show that the proposed method gives the better performance in the accuracy with the same picture quality than conventional rat control algorithm.

• Animal Bioscience
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• 제34권3_spc호
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• pp.449-456
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• 2021

Objective: Seaweeds could be an alternative and functional feed resource. The purpose of this experiment is to investigate the effect of dietary supplementation of Sargassum meal on laying performance and egg quality of layers. Methods: Two hundred 36-wk-old layers were divided into five treatment groups. Each treatment had four replicates with 10 hens per experimental unit. The corn-soybean meal basal diet was formulated as control group. Sargassum meals were included 0%, 1%, 2%, 3%, or 5% to diets for five treatment groups, respectively. Treatment groups were isocaloric-isonitrogenous diets. Laying performance and egg quality were measured for eight weeks. Results: Sargassum meal supplementation did not affect daily feed intake. Supplementation 1% to 3% of Sargassum meal in diets increased daily laying rate and egg mass compared with those from control group (p<0.05). Egg qualities among five groups were all similar. Supplementation of 3% Sargassum meal increased the lightness of egg yolk (p<0.05). Eggs produced from layers fed 1% and 2% Sargassum meal had a higher consumer's acceptability than the control group (p<0.05). In blood characteristics, contents of glucose, nitrogen, triiodothyronine (T3) and thyroxine (T4) increased as the increase of supplementation ratio of Sargassum meal (p<0.05). In serum antibody titers, supplementation of 2% Sargassum meal stimulated a higher immunoglobulin M (IgM) level than that from control group (p<0.05). However, IgM content of layers fed diets with Sargassum meal ≥3% were decreased (p<0.05). There was no difference in IgA and IgG titers among groups. Conclusion: Supplementation of 1% to 3% Sargassum meal has shown to increase egg laying rate and egg mass of Leghorn layers. However, high supplementation (5%) would negatively affect laying performance. In consideration of laying performance, egg quality, consumer responses, and blood antibody, supplementation of Sargassum meal was suggested 2% in the diet for layers.