• Membrane Journal
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• v.17 no.2
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• pp.146-160
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• 2007

A parametric study on pervaporation-facilitated esterification was performed by using a practical model based on non-perfect separation through membrane which is not perfectly permselective to water. Thus, membrane selectivity as well as membrane capability to remove water should be taken into account in establishing the simulation model to explain how the membrane separation influence the esterification reaction process. It was shown by simulation that in the reaction systems with non-perfect separation, the permeation of reactants which are acid or/and alcohol retards the reaction by inducing the backward reaction so that reaction conversion curve is located between a reaction system coupled with pervaporation process having a perfect permselectivity to water and a reaction system without pervaporation process. The volume change of reaction system occurs as a result of the permeation through the membrane. The reaction volume change which can be characterized by the reaction ratio of $r_{\Psi}\;to\;r_{{\Psi}=1}$ affects reaction kinetics by concentrating reactants and products, respectively, with different extent with time; reactant-concentrating effect is dominant during the initial stage of reaction, resulting in facilitating the reaction, and then product-concentrating effect is exerted more on reaction, causing to slow down the reaction. When pervaporative dehydration is applied to the reaction system plays an important role in the reaction as well. The effect of timing to impose pervaporation on reaction system affected the reaction kinetics in terms of reaction rate and reaction conversion. A relationship was derived to explain membrane unit capacity and reaction parameters that will be used as a design tool to determine membrane unit capacity at a given reaction conditions or reaction parameters at a membrane unit capacity.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.16 no.10 s.101
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• pp.1050-1058
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• 2005

This paper presents how to design and implement a very compact, cost effective and broad band receiver module for IEEE 802.16 FWA(Fixed Wireless Access) in the 40 GHz band. The presented receiver module is fabricated in a multi-layer LTCC(Low Temperature Cofired Ceramic) technology with cavity process to achieve excellent electrical performances. The receiver consists of two MMICs, low noise amplifier and sub-harmonic mixer, an embedded image rejection filter and an IF amplifier. CB-CPW, stripline, several bond wires and various transitions to connect each element are optimally designed to keep transmission loss low and module compact in size. The LTCC is composed of 6 layers of Dupont DP-943 with relative permittivity of 7.1. The thickness of each layer is 100 um. The implemented module is $20{\times}7.5{\times}1.5\;mm^3$ in size and shows an overall noise figure of 4.8 dB, an overall down conversion gain of 19.83 dB, input P1 dB of -22.8 dBm and image rejection value of 36.6 dBc. Furthermore, experimental results demonstrate that the receiver module is suitable for detection of Digital TV signal transmitted after up-conversion of $560\~590\;MHz$ band to 40 GHz.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.29 no.10
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• pp.758-765
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• 2018

This paper presents a 24-GHz frequency-modulated continuous wave(FMCW) radar transceiver with two Rx and one Tx channels in 65-nm complementary metal-oxide-semiconductor(CMOS) process and implemented it on a radar system using the developed transceiver chip. The transceiver chip includes a $14{\times}$ frequency multiplier, low-noise amplifier, down-conversion mixer, and power amplifier(PA). The transmitter achieves >10 dBm output power from 23.8 to 24.36 GHz and the phase noise is -97.3 GHz/Hz at a 1-MHz offset. The receiver achieves 25.2 dB conversion gain and output $P_{1dB}$ of -31.7 dBm. The transceiver consumes 295 mW of power and occupies an area of $1.63{\times}1.6mm^2$. The radar system is fabricated on a low-loss Duroid printed circuit board(PCB) stacked on the low-cost FR4 PCBs. The chip and antenna are placed on the Duroid PCB with interconnects and bias, gain blocks and FMCW signal-generating circuitry are mounted on the FR4 PCB. The transmit antenna is a $4{\times}4$ patch array with 14.76 dBi gain and receiving antennas are two $4{\times}2$ patch antennas with a gain of 11.77 dBi. The operation of the radar is evaluated and confirmed by detecting the range and azimuthal angle of the corner reflectors.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.4
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• pp.564-573
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• 2019

Objective: Evaluate the effects of i) dehulling of lupine seed on chemical composition and apparent metabolizable energy (AME) and ii) soybean meal substitution by dehulled lupine seed in broiler diets with enzymes on productive performance, size of digestive organs and welfare-related variables. Methods: Experiment 1, chemical composition and AME were determined in whole and dehulled lupine seed. Experiment 2, two hundred eighty-eight one-day-old male Ross 308 broilers were used. The experimental diets were maize-soybean meal (MS), MS with enzymes (MSE) and maize-dehulled lupine seed with enzymes (MLE). Diets were assigned to the experimental units under a completely randomized design (eight replicates per diet). The body weight (BW) gain, feed intake, feed conversion, digestive organ weights, gait score, latency to lie down and valgus/varus angulation were evaluated. Results: The dehulling process increased protein (25.0% to 31.1%), AME (5.9 to 8.8 MJ/kg) and amino acid contents. The BW gain of broilers fed the MLE diet was similar (p>0.05) to that of those fed the MS diet, but lower than that of those fed the MSE diet. Feed intake of broilers fed the MLE diet was higher (p<0.05) than that of those fed the MS diet and similar (p>0.05) to those fed the MSE diet. Feed conversion of broilers fed the MLE diet was 8.0% and 8.7% higher (p<0.05) than that of those fed the MS and MSE diets, respectively. Broilers fed the MLE diet had the highest (p<0.05) relative proventriculus and gizzard weights, but had poor welfare-related variables. Conclusion: It is possible to substitute soybean meal by dehulled lupine seed with enzymes in broiler diets, obtaining similar BW gains in broilers fed the MLE and MS diets; however, a higher feed intake is required. Additionally, the MLE diet reduced welfare-related variables.

• Journal of Advanced Navigation Technology
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• v.21 no.4
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• pp.413-421
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• 2017

In this paper, we designed and fabricated a compact UHF receive module for efficient operation such as tactical and operation situation, target location information confirmation, target reset using Link-K(Korean joint tactical data link system). And the effect of target reset was analyzed by simulation. The designed module consists of UHF(ultra high frequency) receiver section, control section, and power distribution section. The UHF receiver section performs frequency down conversion, filtering and automatic gain control, etc. The control section demodulates frequency down-converted signals, extracts information, and performs external interworking. The power distribution section supplies external power, generates and supplies the power required by each section. The fabricated module was dimension of $105{\times}105{\times}80mm$ and weighed 1.10 kg and The receiving distance is more than 50 km.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.39 no.4
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• pp.106-116
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• 2016

MTO (Make to Order) is a manufacturing process in which manufacturing starts only after a customer's order is received. Manufacturing after receiving customer's orders means to start a pull-type supply chain operation because manufacturing is performed when demand is confirmed, i.e. being pulled by demand (The opposite business model is to manufacture products for stock MTS (Make to Stock), which is push-type production). There are also BTO (Build to Order) and ATO (Assemble To Order) in which assembly starts according to demand. Lean manufacturing by MTO is very efficient system. Nevertheless, the process industry, generally, which has a high fixed cost burden due to large-scale investment is suitable for mass production of small pieces or 'mass customization' defined recently. The process industry produces large quantities at one time because of the lack of manufacturing flexibility due to long time for model change or job change, and high loss during line-down (shutdown). As a result, it has a lot of inventory and costs are increased. In order to reduce the cost due to the characteristics of the process industry, which has a high fixed cost per hour, it operates a stock production system in which it is made and sold regardless of the order of the customer. Therefore, in a business environment where the external environment changes greatly, the inventory is not sold and it becomes obsolete. As a result, the company's costs increase, profits fall, and it make more difficult to survive in the competition. Based on the customer's order, we have built a new method for order system to meet the characteristics of the process industry by producing it as a high-profitable model. The design elements are designed by deriving the functions to satisfy the Y by collecting the internal and external VOC (voice of customer), and the design elements are verified through the conversion function. And the Y is satisfied through the pilot test verified and supplemented. By operating this make to order system, we have reduced bad inventories, lowered costs, and improved lead time in terms of delivery competitiveness. Make to order system in the process industry is effective for the display glass industry, for example, B and C groups which are non-flagship models, have confirmed that the line is down when there is no order, and A group which is flagship model, have confirmed stock production when there is no order.

• Journal of the Institute of Electronics and Information Engineers
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• v.49 no.10
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• pp.159-168
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• 2012

In this paper, a W-band single-chip receiver MMIC for FMCW(Frequency-modulated continuous-wave) radar is presented using $0.15{\mu}m$ GaAs pHEMT technology. The receiver MMIC consists of a 4-stage low noise amplifier(LNA), a down-converting mixer and a 3-stage LO buffer amplifier. The LNA is designed to exhibit a low noise figure and high linearity. A resistive mixer is adopted as a down-converting mixer in order to obtain high linearity and low noise performance at low IF. An additional LO buffer amplifier is also demonstrated to reduce the required LO power of the W-band mixer. The fabricated W-band single-chip receiver MMIC shows an excellent performance such as a conversion gain of 6.2 dB, a noise figure of 5.0 dB and input 1-dB compression point($P_{1dB,in}$) of -12.8 dBm, at the RF frequency of $f_0$ GHz, LO input power of -1 dBm and IF frequency of 100 MHz.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.11
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• pp.1616-1624
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• 2016

The aim of present experiment was to investigate the effect of protein reduction in commercial broiler chicken rations with incorporation of de-oiled rice bran (DORB) and supplementation of limiting amino acids (valine, isoleucine, and/or tryptophan) with ration formulation either on total amino acid (TAA) or standardized ileal digestible amino acids (SIDAA). The experimental design consisted of $T_1$, TAA control; $T_2$ and $T_3$, 0.75% and 1.5% protein reduction by 3% and 6% DORB incorporation, respectively by replacing soybean meal with supplemental limiting amino acids to meet TAA requirement; $T_4$, SIDAA control, $T_5$ and $T_6$, 0.75% and 1.5% protein reduction by DORB incorporation (3% and 6%) with supplemental limiting amino acids on SIDAA basis. A total of 360 dold fast growing broiler chicks (Vencobb-400) were divided into 36 homogenous groups of ten chicks each, and six dietary treatments described were allocated randomly with six replications. During 42 days trial, the feed intake was significantly (p<0.05) reduced by TAA factor compared to SIDAA factor and protein factor significantly (p<0.05) reduced the feed intake at 1.5% reduction compared to normal protein group. This was observed only during pre-starter phase but not thereafter. The cumulative body weight gain (BWG) was significantly (p<0.05) reduced in TAA formulations with protein step-down of 1.5% ($T_3$, 1,993 g) compared to control ($T_1$, 2,067 g), while under SIDAA formulations, BWG was not affected with protein reduction of 1.5% ($T_6$, 2,076 g) compared to $T_4$ (2,129 g). The feed conversion ratio (FCR) was significantly (p<0.05) reduced in both TAA and SIDAA formulations with 1.5% protein step-down ($T_3$, 1.741; $T_6$, 1.704) compared to respective controls ($T_1$, 1.696; $T_4$, 1.663). The SIDAA formulation revealed significantly (p<0.05) higher BWG (2,095 g) and better FCR (1.684) compared to TAA formulation (2,028 g; 1.721). Intake of crude protein and all limiting amino acids (SID basis) was higher in SIDAA group than TAA group with resultant higher nitrogen retention (4.438 vs 4.027 g/bird/d). The nitrogen excretion was minimized with 1.5% protein reduction (1.608 g/bird) compared to normal protein group (1.794 g/bird). The serum uric acid concentration was significantly reduced in $T_3$ (9.45 mg/dL) as compared to $T_4$ (10.75 mg/dL). All carcass parameters were significantly (p<0.05) higher in SIDAA formulation over TAA formulation and 1.5% protein reduction significantly reduced carcass, breast and thigh yields. In conclusion, the dietary protein can be reduced by 0.75% with TAA formulation and 1.5% with SIDAA formulation through DORB incorporation and supplementation of limiting amino acids and among formulations, SIDAA formulation was better than TAA formulation.

• Journal of Energy Engineering
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• v.25 no.3
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• pp.27-33
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• 2016

The heat recovery system that was applied in this study, is the energy-saving type that can produce the maximum cooling capacity less power in use. In order to have a more precise control function the temperature and humidity of the constant temperature and humidity machine, control algorithm is applied to designed a fuzzy PID controller, and the outside air compensation device (air-cooled) demonstrated excellent ability to dehumidify the moisture, $-20^{\circ}C$ in winter. High efficiency and the low-noise type sirocco fan operate quitely and designed to fit the bottom-up and top-down in accordance with the characteristics of equipment. as a result of experiment data, the conversion efficiency is 95% or more, power recovery time is within 5sec, stop delay time is within 30sec, pump down time is 10sec, pump delay time is 5sec, heating delay time is 5sec, temperature deviation is ${\pm}2^{\circ}C$ (cooling deviation: $2^{\circ}C$, Heating deviation : $2^{\circ}C$), humidity deviation is a ${\pm}5%$ (humidification deviation 3.0%, dehumidification deviation 3.0%). Recently, ubiquitous technology is important. so, the constant temperature and humidity machine designed to be able to remotely control to via the mobile phone, and more scalable to support MMI software and automatic interface. Further, the life of the parts and equipment is extended by the failure.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.2C
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• pp.209-216
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• 2009

The repeater for wireless broadband internet (Wibro) system using OFDM demands the short processing delay to eliminate inter-symbol interference resulted from the time delay greater than the guard time. Towards this, the total system delay of repeater is expected to be minimized as possible as it can without distorting signal quality. In general, the FIR-type of filter is commonly deployed as a channelization filter, but due to its large amount of coefficients for producing prerequisite filter response the excessive large time delay occurs. To withstand this problem, the paper proposes the method for designing IIR filter whose response almost identical to that of the original filter. Moreover, in order to linearize the phase response of the designed IIR filter, this paper also introduce the way of designing the all-pass filter to be cascaded works for linearizing phase response of the channelization as well as the de-channelization filter. To achieve the further improvement in linearization of the phase response and reduction of the overall complexity, this paper tries to transform the integrated IIR filter group into the structure in polyphase style. The computer simulation verifies that the integrated IIR filter group designed in this paper reveals the relatively short processing delay without harming the acceptible signal quality.