• 상하수도학회지
• /
• 제20권4호
• /
• pp.637-643
• /
• 2006

The bench-scale chlorine exposure study was performed to investigate the effect of pretreatment by free chlorine and monochloramine ($NH_2Cl$) on the performance of RO membranes made of polyamide (PA). Feed monochloramination at 2mg/L did not cause significant productivity loss compared to free chlorine. However, metal coagulants reacted with monochloramine, the PA membrane suffered from a gradual loss of membrane integrity by chlorine oxidation, which was characterized as a decrease in salt rejection. Especially, RO membranes exposed to alum coagulants with monochloramine revealed the salt rejection lower than those exposed to iron coagulants. XPS membrane surface analysis demonstrated that the chlorine uptake on the membrane surface increased and carbon peaks were shifted significantly when exposed to alum coagulants with monochloramine.

• Asian-Australasian Journal of Animal Sciences
• /
• 제14권12호
• /
• pp.1763-1768
• /
• 2001

The combined effects of low voltage electrical stimulation (ES) and early short-term temperature conditioning on meat quality of Hanwoo beef (Korean native cattle) during storage were investigated. Shear force was influenced by ES and aging. Combination of ES and the $30^{\circ}C$ conditioning resulted in higher myofibril fragmentation index and improved lightness. There was no substantial difference in drip loss among treatments but ES samples showed higher cooking loss than control. Negative effect on shelf-life was not found by early short-term high temperature conditioning. Therefore, the meat quality of Korean native cattle was effectively improved by the combination of ES and the $30^{\circ}C$ conditioning.

• Journal of Advanced Marine Engineering and Technology
• /
• 제31권8호
• /
• pp.954-960
• /
• 2007

The purpose of this paper is to obtain design method of air-distribution system. Air-distribution system is composed of blower, duct, diffusers and measuring equipment. The air-flow rate from each diffuser is not equal. The air-flow rate is calculated with the combined equations which are Bernoulli's equation, continuity equation and minor loss equations. Inlet condition and outlet condition are adapted in each duct system. Then square difference between function of maximum air-flow rate and minimum air-flow rate is used as an object function. Area of diffuser and velocity are established as constraints. To minimize the object function, the optimization method is used. After optimization the design variables are selected under satisfaction of constraints. The air-distribution system is calculated again with the result of optimized design variable. It is shown that the air-distribution system has the equal air-flow rate from diffusers.

• Communications for Statistical Applications and Methods
• /
• 제21권2호
• /
• pp.161-168
• /
• 2014

In mixture experiments with process variables, we consider the case that some of process variables are either uncontrollable or hard to control, which are called noise variables. Given the such mixture experimental data with process variables, first we study how to search for candidate models. Good candidate models are screened by the sequential variables selection method and checking the residual plots for the validity of the model assumption. Two methods, which use numerical optimization methods proposed by Derringer and Suich (1980) and minimization of the weighted expected loss, are proposed to find a cost-effective robust optimal condition in which the performance of the mean as well as the variance of the response for each of the candidate models is well-behaved under the cost restriction of the mixture. The proposed methods are illustrated with the well known fish patties texture example described by Cornell (2002).

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제6권4호
• /
• pp.1006-1025
• /
• 2012

Improving the quality of service in IP networks is a major challenge for real-time voice communications. In particular, packet arrival-delay variation, so-called "jitter," is one of the main factors that degrade the quality of voice in mobile devices with the voice-over Internet protocol (VoIP). To resolve this issue, a receiver-based enhanced timing recovery algorithm combined with active jitter estimation is proposed. The proposed algorithm copes with the effect of transmission jitter by expanding or compressing each packet according to the predicted network delay and variations. Additionally, the active network jitter estimation incorporates rapid detection of delay spikes and reacts to changes in network conditions. Extensive simulations have shown that the proposed algorithm delivers high voice quality by pursuing an optimal trade-off between average buffering delay and packet loss rate.

• 전자공학회논문지A
• /
• 제32A권7호
• /
• pp.43-50
• /
• 1995

In this paper, the variational method are used for the filter analysis methods and a CAD program for the design of the waveguide low-loss bandpass filters using inductive window structures for the VSAT(Very Small Aperture Terminal) system has been developed based on the passband correction method combined with fiter synthesis procedures. Using the developed CAD program, 0.01dB equi-ripple chebyshev type 6-section bandpass filters which are sued in the VSAT system operating nationally are designed for the purpose of the Down-link of 12.75~13.25GHz and the Up-link of 14.0~14.5GHz, fabricated and mesured. The measured results are good agreement woth the theoretical resuls.

• Journal of Mechanical Science and Technology
• /
• 제20권10호
• /
• pp.1590-1606
• /
• 2006

Slider bearings are widely applied in mechanical systems, where the design needs cover increased load capacity, lowered friction and power consumption and creative designs. This work is governed to perform a parametric characterization, by generating a novel structure on the upper slider surface, which can formally be expressed in micro-machined wavy-form, where the individual and combined influences of various structural design parameters and boundary conditions, on the performance records, are also evaluated. Computations put forward that the contribution of the wave amplitude on power loss values is highly dependent on the level of inlet pressure; higher amplitudes are determined to increase power loss in the lowest inlet pressure case of 1.01, whereas the contrary outcome is determined in the higher inlet pressure cases of 3.01 & 5.01. Designing the slider bearing system, based on optimal load capacity, produced the optimum wave number ranges as 10-45, 7-11 and 5-8 for the pad inclinations of $5^{\circ},\;4^{\circ}$ and $3^{\circ}$ respectively.

• Journal of information and communication convergence engineering
• /
• 제3권1호
• /
• pp.23-27
• /
• 2005

In this paper, the effects of various annealing conditions on the resonance characteristics of ZnO-based FBAR devices are compared. Several FBAR device samples were fabricated by using three different annealing methods while one sample remained non-annealed as a reference for comparison. Return loss ($S_11$) could be significantly improved by both Bragg reflector-annealing and/or post-annealing. Especially, the use of the combined annealings resulted in most desirable resonance improvement compared with the Bragg reflector-annealing or post-annealing method alone.

• 한국식품영양학회지
• /
• 제12권4호
• /
• pp.380-386
• /
• 1999

Fermented sausages inoculated with starter cultures which were combined Lactobacillus curvatus and Staphylococcus carnosus(LCSC), Lactobacillus plantarum and Staphylococcus carnosus(LPSC) were manufac-tured. changes in chemical composition salinity weight loss fatty acids inosine monophosphate(IMP) and hypoxanthine (Hx) and fee amino acids during ripening of fermented sausages were investigated. Due to drying the water content was decreased while the protein and fat contents salinity and weight low were increased during ripening. No significant differences between LCSC and LPSC were found for chemical composition salinity and weight loss. During ripening unsaturated fatty acid contents was dec-reased while saturated fatty acid contents was increased. At the end of the ripening the levels of mon-oenes were slightly higher in the LPSC than in the LCSC. In both treatments IMP contents were dec-reased but no changes were observed in Hx contents during ripening. Due to ripening the increase in total and individual free amino acids were observed and contents of glutamic acid alanine leucine and lysine were greatly increased.

• 한방비만학회지
• /
• 제3권1호
• /
• pp.17-24
• /
• 2003

Obesity increases the risk of knee and to a lesser extent hip OA, which combined affect a large percentage of middle-aged and elderly adults and which are major source of disability, and factor of drop a lowering in the physical exercise ability. Energy expenditure from physical activity accounts for up to 30% of total energy expenditure, it can have a significant impact on energy balance. We studied a exercise therapy that improved long-term weight management and produced additional benefits - loss of joint pain, improved joint mobility, and this exercise program will enhance the weight loss and health benefits from physical activity in the treatment of obese patients with osteoarthritis.