• Journal of the Korean Society of Manufacturing Process Engineers
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• v.15 no.3
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• pp.93-101
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• 2016

This study presents a simple genetic algorithm to systematically design a PID controller for a hydraulic positioning system operated by a proportional solenoid valve. The inverse dead-zone compensator with nonlinear characteristics is used to cancel out the dead-zone phenomenon in the hydraulic system. The object function considering overshoot, settling time, and control input is adopted to search for optimal PID gains. The designed PID controller is compared with the LQG/LTR controller to check the performance of the hydraulic positioning system in the time and frequency domains. The experimental results show that the hydraulic servo system with the proposed PID controller responds effectively to the various types of reference input.

• Journal of the Korea Convergence Society
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• v.9 no.7
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• pp.199-203
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• 2018

Because of emission control of greenhouse gas, shipbuilders, especially those in Korea, are pushing forward to introduce eco-friendly ship-building technology utilizing LNG. However, Technical skills of domestic shipbuilders in manufacturing the cryogenic pump designed to supply LNG for vessels are so low that technical skills for design and manufacturing of core parts are in urgent need. Therefore, This study described about the Rotor as a core part of cryogenic submerged centrifugal pump for ship LNG supply system. We wish to utilize for the basic data to develop the technology for the Rotor as deducing the optimal outcome with the experimental and the analytical methods in material selection.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.25 no.1
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• pp.7-13
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• 2013

Bio Clean Room(BCR) and pharmaceutical product manufacturing facilities require careful assessment of many factors, including HVAC, controls, room finishes, process equipment, room operations, and utilities. Flow of equipment, personnel, and product must also be considered along with system flexibility, redundancy, and maintenance shutdown strategies. It is important to involve designers, operators, commissioning staff, quality control, maintenance, constructors, validation personnel, and the production representative during the conceptual stage of design. Critical variables for room environment and types of controls vary greatly with the clean space's intended purpose. It is particularly important to determine critical parameters with quality assurance to set limits and safety factors for temperature, humidity, room pressure, and other control requirements. In this paper, oxygen cluster ion equipment was utilized in order to enhance the indoor air quality and to prevent the airborne infection of ward in hospital. Moreover, the performance test of the equipment was also performed in order to develop the optimal sterilization system of BCR using the equipment.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.1
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• pp.135-142
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• 2015

This study was conducted to evaluate the effect of inclusion of propolis extraction residue in the feed of broilers from 1 to 21 d of age on phagocytic activity of macrophages, cutaneous basophil hypersensitivity response to phytohemagglutinin, antibody production against Newcastle disease, lymphoid organ weight and hematological profile and to determine the optimal level of inclusion. 120 chicks, reared in metabolism cages until 21 days of age, were distributed in a completely randomized design, with five treatments (0%, 1%, 2%, 3%, and 4% of propolis residue) and six replications. The relative weight of thymus and monocyte percentage were affected by propolis residue, with a quadratic response (p<0.05) and lowest values estimated at 2.38% and 2.49%, respectively. Changes in relative weight of cloacal bursa and spleen, percentage of lymphocyte, heterophil, basophil, eosinophil, and heterophil:lymphocyte ratio, antibody production against Newcastle disease, phagocytic activity of macrophages and the average number of phagocytosed erythrocytes were not observed. The nitric oxide production with regard to positive control (macrophages+erythrocytes) decreased linearly (p<0.05) with increased doses of propolis residue. The remaining variables of nitric oxide production (negative control - macrophages, and difference between the controls) were not affected by propolis residue. The cutaneous basophil hypersensitivity response to phytohemagglutinin as determined by the increase in interdigital skin thickness exhibited a quadratic response (p<0.05), which predicted a lower reaction response at a dose of 2.60% of propolis residue and highest reaction response after 43.05 hours of phytohemagglutinin injection. The inclusion of 1% to 4% of propolis extraction residue in broiler diets from 1 to 21 days of age was not able to improve the immune parameters, despite the modest changes in the relative weight in thymus, blood monocyte percentage, nitric oxide concentration, and interdigital reaction to phytohemagglutinin.

• Journal of Biosystems Engineering
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• v.38 no.3
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• pp.215-221
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• 2013

Purpose: Opuntia Humifusa has been used in the food and beauty industry after removing spines and glochids clearly. This study compared the methods used in removing spines and analyzed the design factors for developing a spine removal device. Method: This study compared the spine removal ratios in accordance with the length of brush, water spray pressure, the number of water spray, and the size of Opuntia Humifusa in a rotating brush device and a water spray device. In addition, this study compared the reversal ratios according to the inclination angle of a conveyor, the drop height of Opuntia Humifusa, and the speed of the conveyor to analyze the reversal factors. Results: The spines were not removed clearly in the rotating brush method, and the glochids were nailed deeply. The spine removal ratio was 96.9% with the water spray pressure of 20 $kgf/cm^2$ and the conveyor speed of 10 cm/s in the water spray method. The number of water spray was correlated with the spine removal ratio, and the average spine removal ratio was 95.6% with three cycles of water spray. The reversal ratio was 97% with the inclination angle of the conveyor $20^{\circ}$, the drop height of 380 mm, and the conveyor speed of 10 cm/s. Conclusions: In order to develop a Opuntia humifusa spine removing device, this study compared the rotating brush and water spray methods. As a result, each spine removal performance of the rotating brush and water spray methods was 96.9% and 95.6%, respectively. Although the performance of the rotating brush method was slightly higher than that of the water spray method, the water spray method was suitable for removing spines from stem because the epidermis of stem was damaged and the glochids were nail deeply in the rotating brush method. Further studies on appropriate arrangement of spray nozzles, maintaining the optimal water spray pressure, the speed and angle control of the feeding conveyor, and devices for inducing the stem to the center will be needed in combining the water spray device and the reversal device.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.9 no.1
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• pp.27-44
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• 2002

The main purpose of this study was to identify the effect of hand massage on pain and anxiety related to chest tube removal in patients with a lobectomy. The research design of this study was a nonequivalent control group non-synchronized design. Of the twenty nine adult subjects, fourteen were assigned to the experimental group and fifteen to the control group. The data were obtained over 3 months from a medical center in Seoul. The instruments used to assess trait state anxiety was the Spielberger Trait-State anxiety Inventory. For pain and psychological anxiety. The Visual Analogue Scale was used. Hiko analogue sphygmo-manometer(2001) was used to check blood pressure and pulse rate as indicators of physiological anxiety Subjects in the experimental group received hand massage for 5 minutes just before chest tube was removed, and subjects assigned to the control group did not receive hand massage. Data were analysed with $x^2$-test and Mann-Whitney U test using the SPSSWIN 10.0 program. The results of the study are as follows : 1. Hypothesis 1: 'there will be a significant difference between two groups in the level of pain after chest tube removal' was supported (u = 23.00, p < 0.001). 2. Hypothesis 2: 'there will be a significant difference between the two groups in the level of psychological anxiety after chest tube removal' was supported (u = 3.00, p < 0.001). 3. Hypothesis 3: 'there will be a significant difference between the two groups in physiological anxiety(systolic, diastolic blood pressure and pulse rate) after chest tube removal' was supported(u =55.50, p = 0.01 ; u = 41.50, p = 0.01 ; u = 20.50, p < 0.001, relatively). The findings of this study indicate that hand massage is effective for pain and anxiety related to chest tube removal in patients with lobectomy. Therefore, hand massage is recommended as an effective nursing intervention for relieving pain and anxiety in patients undergoing chest tube removal. Further research is needed to identify the proper duration and timing to achieve the optimal effect of hand massage. A larger subject population is required to apply the current findings to the general population. Further research is also needed to assess the effects of hand massage in other patient subsets. Finally, it would be interesting to see if the effects of hand massaging would be attenuated when performed by a non-medical specialist.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.6
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• pp.869-879
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• 2021

Methods for the development of home meal replacement seafood tailored to consumer needs for the advanced use of Broughton's ribbed ark Scapharca broughtonii (BRA) in Korea are required. In this study, we developed a cheese-topped, semi-dried, and seasoned Broughton's ribbed ark (S-BRA) tailored for the younger generation with an improved texture and fish odor. The optimization of conditions to improve the texture and fish odor was performed using RSM. The design of the model was appropriate because there was no significant difference (P>0.05) between the predicted and actual values of moisture content, hardness, and overall acceptance, and the optimal preparation conditions were a vinegar content of 2.68%, a soaking time of 62 min, a drying temperature of 60℃, and a time of 162 min. The S-BRA manufactured under these optimal conditions exhibited a lower odor intensity compared to the unsoaked and undried control, suggesting that the fish odor of S-BRA has been improved. The moisture content related to the texture of the S-BRA was lower than that of the control, and the hardness was higher. Therefore, the S-BRA developed in this study will appeal to people of all ages, especially the younger generation; their consumption is expected to increase.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.3
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• pp.338-345
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• 2001

An experiment was conducted to determine the optimal inclusion ratio of spray dried plasma protein (SDPP) and dried porcine solubles (DPS) for maximizing growth and improving immunity in weaned pigs. One hundred-fifty male (barrow) pigs were allotted in a completely randomized block design. Treatments were as follows: 1) control (6% SDPP), 2) S6D6 (6% SDPP+6% DPS), 3) S6D3 (6% SDPP+3% DPS), 4) S3D6 (3% SDPP+6% DPS) and 5) S3D3 (3% SDPP+3% DPS). Each treatment has 6 replicates with 5 pigs per replicate. Average daily gain (ADG) and average daily feed intake (ADFI) were highest, but not significantly different when pigs were fed a diet contained 6% SDPP and DPS from d 0 to 7 after weaning. Pigs fed the S6D3 diet showed better weight gain and feed intake than other treatments, especially compared with pigs fed S3D6 diet (p<0.05) from d 8 to 21 after weaning. For the overall experimental period, pigs fed the S6D3 diet showed the best improvement in ADG and ADFI. The digestibilities of dry matter (DM) and crude protein (CP) were higher in pigs fed the S6D6 diet than other diets from d 0 to 7 after weaning. However, pigs fed S6D3 diet showed higher DM, CP and essential amino acids (except methionine and arginine) digestibilities than pigs fed other diets from d 8 to 21 after weaning, although there was no significant difference. From d 8 to 21 after weaning, threonine, valine, isoleucine and leucine digestibilites were higher in S6D6 group, and phenyalanine, histidine, lysine and arginine digestibility were higher in S6D3 group than other groups. The ratio of CD4 and CD8 positive lymphocytes during the overall experimental period was independent of the ratio of SDPP and DPS. However, CD4+:CD8+ ratio was numerically lowered in pigs fed diet the S6D3 diet. Therefore, the present study suggests that an optimal inclusion ratio for maximizing growth performance and maintaining low immune status is 6% of SDPP and 3% of DPS in weaned pigs.

• Journal of the Korea Institute of Military Science and Technology
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• v.14 no.3
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• pp.423-431
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• 2011

Warfighting experimentation is an important process for identifying requirements against changing military environment and for verifying proposed measures for reforming military service. The wargame simulation experiment is regarded as one of the most effective means to warfighting experimentation, and its importance is increasing than ever. On the other hand, the results of wargame experiments could be unreliable due to the uncertainty involved in the experimental procedure. To improve the reliability of the experimental results, systematic experimental procedures and analysis methods must be employed, and the design and analysis of experiments technique can be used effectively for this purpose. In this paper, AWAM, a wargame simulator, is used to optimize the organization of operational troops. The simulation model describes a warfighting situation in which the 'survival rate of our force' and the 'survival rate of the enemy force' are considered as responses, 'the numbers of weapons in the squad' as control factors, and 'the uncontrollable variables of the battlefield' as noise factors. In addition, for the purpose of effective experimentation, the product array approach in which the inner and outer orthogonal arrays are crossed is adopted. Then, the signal-to-noise-ratio for each response and the desirabilities for the means and standard deviations of responses are calculated and used to determine a compromise optimal solution. The experimental procedures and analysis methods developed in this paper can provide guidelines for designing and analyzing wargame simulation experiments for similar warfighting situations.

• Structural Engineering and Mechanics
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• v.83 no.5
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• pp.655-669
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• 2022

Passive vibration control devices like tuned liquid column dampers (TLCD) not only significantly reduce buildings' vibrations but also can serve as a water storage facility. The recently introduced modified form of TLCD known as tuned liquid column ball damper (TLCBD) suppressed external vibration efficiently compared to traditional TLCD. For excellent performance, the mass ratio of TLCBD should be in the range of 5% to 7%, which does not include the mass of the ball. This additional mass of the ball increases the overall structure mass. Therefore, in this paper, an effort is made to reduce the mass of TLCBD. For this purpose, a new modified version of TLCBD known as tuned liquid column hollow ball damper (TLCHBD) is proposed. The existing mathematical modeling of TLCBD is used for this new damper by updating the numerical values of the mass and mass moment of the ball. Analytically the optimal design parameters are obtained. Numerically the TLCHBD is investigated with a single degree of freedom structure under harmonic and seismic loadings. It is found that TLCHBD performance is similar to TLCBD in both loadings' cases. To validate the numerical results, an experimental study is conducted. The mass of the ball of TLCHBD is reduced by 50% compared to the ball of TLCBD. Both the arrangements are studied with a multi-degree of freedom structure under harmonic and seismic loadings using a shake table. The results of the experimental study confirm the numerical findings. It is found that the performance behavior of both the dampers is almost similar under harmonic and seismic loadings. In short, the TLCHBD is lighter in weight than TLCBD but has a similar vibration suppression ability.