• Korean Journal of Organic Agriculture
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• v.26 no.1
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• pp.141-149
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• 2018

This experiment was conducted to investigate the effects of multi-enzyme on growth performance, intestinal morphology, and nutrient digestibility of weaned pigs. A total 36 weaned pigs ($5.92{\pm}0.48kg\;BW$; 28 d old) were randomly allotted to 2 dietary treatments (3 pigs/pen, 6 replicates/treatment) in a randomized complete block design. The dietary treatments were a typical diet based on corn and soybean meal (CON) and CON with 0.1% multi-enzyme (Multi; mixture of ${\beta}-mannanase$, xylanase, ${\alpha}-amylase$, protease, ${\beta}-glucanase$, and pectinase). Pigs were fed their respective diets for 6 wk. Measurements were growth performance, morphology of ileum, apparent ileal digestibility and apparent total tract digestibility of dry matter, crude protein, and energy of weaned pigs. There were no significant differences on growth performance during overall experimental period. No differences were found for the morphology of ileum and nutrient digestibility between CON and Multi groups. Therefore, the results in the current study indicated that multi-enzyme supplementation in diets had no effects on growth performance, intestinal morphology, and nutrient digestibility of weaned pigs.

• Economic and Environmental Geology
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• v.52 no.5
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• pp.347-356
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• 2019

Various studies regarding the sedimentary environment, depositional age, provenance, and metamorphic history have been carried out on the Taean Formation in the western part of Gyeonggi Massif, since the unique detrital zircon age pattern was revealed. This review paper introduces the previous researches on the Taean Formation and discusses the depositional age and provenance. The Taean Formation was traditionally regarded as a Precambrian stratigraphic unit, but recently it is interpreted to be a middle or upper Paleozoic formation due to the occurrence of large amounts of Early to Middle Paleozoic detrital zircons. The Taean Formation consists of metasandstone, argillaceous schist, and phyllite which are mainly made up of quartz and mica. The protoliths are interpreted as turbidites deposited in deep sea fan environment. The Taean Formation has been interpreted to be deposited between the Devonian to Triassic ages given the age differences between detrital zircons and intrusive rocks. There are two opinions that the deposition age is close to the Devonian or the Permian period. The provenance of this formation is supposed to be South China block, Chinese collisional belt, or Gyeonggi Massif. Given the available detrital zircon ages of the Taean Formation and other Korean (meta)sedimentary rocks, the Taean Formation shares major source rocks with Yeoncheon Group and Pibanryeong Unit of the Okcheon Supergroup, but their source regions are not entirely consistent. Considering the existing hypotheses about the depositional timing and provenance, we put weight on the possibility that the Taean Formation was deposited between Permian and Early Triassic periods. However, further studies on the stratigraphy and sedimentary petrology are needed to clarify its definition and to elucidate the provenance.

• Journal of the Korean Society for Railway
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• v.17 no.5
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• pp.328-335
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• 2014

Numerical prediction methods were applied to investigate the turbulent air currents and air-conditioning efficiency in an underground subway station, and the results compared to experimental data. The Shin-gumho Station($8^{th}$ floor underground and 43.6m in depth) in Seoul was selected for the analysis. The entire station was covered for simulation and the ventilation mode was ordinary. The ventilation diffusers were modeled as 95 square shapes of $0.6m{\times}0.6m$ in the lobby and as 222 square shapes in the platform. Cooling air of $47,316m^3/h$ was supplied and the returned air of $33,980m^3/h$ is exhausted in the lobby and the cooling air of $33,968m^3/h$ is supplied and the returned air of $76,190m^3/h$ was exhausted in the platform which is the same as the experimental data. The cases of the screen-door-closed and open were respectively investigated. A total of 7.5million grids were generated and the whole domain divided into 22 blocks for MPI efficiency of calculation. Large eddy simulation (LES) was applied to solve the momentum and energy equation.

• Journal of the Korean Institute of Gas
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• v.25 no.3
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• pp.27-38
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• 2021

We devised the system to automatically shutdown the boiler and to fundamentally block the harmful gases, including carbon monoxide, into the indoor when the exhaust system swerves: (1) The discharge pressure of the exhaust gas decreases when the exhaust pipe is disconnected. The monitoring system of the exhaust pipe is implemented by measuring the output voltage of APS(Air Pressure Sensor) installed to control the amount of combustion air. (2) The operating software was modified so that when the system recognizes the fault condition of a flue pipe, the boiler control unit displays the fault status on the indoor regulator while shutting down the boiler. In accordance with the ventilation facility standards in the "Rules for Building Equipment Standards" by the Ministry of Land, Infrastructure and Transport, experiments were conducted to ventilate indoor air. When carbon monoxide leaked in worst-case scenario, it was possible to prevent poisoning accidents. However, since 2013, the number of indoor air exchange times has been mitigated from 0.7 to 0.5 times per hour. We observed the concentration exceeding TWA 30 ppm occasionally and thus recommend to reinforce this criterion. In conclusion, if the flue pipe fault detection and the indoor air ventilation system are introduced, carbon monoxide poisoning accidents are expected to decrease significantly. Also when the manufacturing and inspection steps, the correct installation and repair are supplemented with the user's attention in missing flue, it will be served to prevent human casualties from carbon monoxide poisoning.

• Journal of the Korea Convergence Society
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• v.10 no.3
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• pp.49-57
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• 2019

The core technology development of the Fourth Industrial Revolution is linked to the development of other core technologies, which will change the industrial structure in the future and create a new smart business model. In this paper, tried to analyze the technology maturity level and analyze the technology maturity. To do this, used technology trend information to investigate and integrate the market, policy, etc. Of core technology of the 4th Industrial Revolution to achieve a comprehensive maturity level. Because technology maturity measures are scored by technology developers, prejudices may be acted upon according to a person's tendency, which may be a subjective evaluation. It is also a measure of the maturity of individual technologies, and thus is not suitable for evaluating the overall system integration perspective. However, it is possible to evaluate the maturity before integrating the core element technologies constituting the whole system and to use it as a means to compare the effect of the whole system and its feasibility and play an important role in the planning of technology development.

• Journal of Animal Science and Technology
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• v.61 no.2
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• pp.77-86
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• 2019

The supplementation level of barley was limited because of high contents of fiber in monogastric animals. Barley contained high soluble fiber, thus it could prevent to diarrhea of weaning pigs. Moreover, as the barley break down by enzymes, free sugars come out from the barley, which could be used as an energy source in weaning pigs and replace milk by-products in weaning pig's diet. Therefore, present study was conducted to investigate the influence of barley to replace milk by-product in weaning pig's diet on growth performance, blood profile, nutrient digestibility, diarrhea incidence, and economic analysis in weaning pigs. A total of 112 crossbred ($[Yorkshire{\times}Landrace]{\times}Duroc$, weaned at 28 days of age) piglets were allotted to 4 treatments in a randomized complete block (RCB) design. Each treatment has 7 replications with 4 pigs per pen. Pigs were fed each treatment diet which containing different levels of barley (0%, 10%, 20%, and 30%) at the expense of whey powder and lactose. Three phase feeding programs were used for 6 weeks of growth trial (phase 1: 0-2 weeks; phase 2: 3-4 weeks; phase 3: 5-6 weeks). During 0-2 week, body weight (BW), average daily gain (ADG) and G:F ratio were decreased as barley level increased in the diet (linear response, p < 0.01). In blood profile, blood urea nitrogen was decreased as the barley level increased in the diet (linear, p < 0.01). However, no significant differences were observed in blood glucose level. In nutrient digestibility, crude fat digestibility was linearly increased as barley increased (linear, p < 0.01). The incidence of diarrhea was improved as increasing barley contents in all phases (linear, p < 0.01). These results demonstrated that supplementation of barley to replace milk by-product influenced negatively on growth performance during 0-2 week. However, the incidence of diarrhea and later growth performance from 3 week postweaning were improved as dietary barley level increased.

• Journal of Animal Science and Technology
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• v.63 no.3
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• pp.520-530
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• 2021

This experiment was performed to verify whether dietary heat-killed Lactobacillus rhamnosus (LR) improves growth performance and modulates immune responses of weaned pigs. Ninety-six weaned pigs ([Landrace × Yorkshire] × Duroc; 6.95 ± 0.25 kg body weight [BW]; 28 d old) were randomly allocated to four treatments: 1) a basal diet without heat-killed LR (CON), 2) T1 (CON with 0.1% heat-killed LR), 3) T2 (CON with 0.2% heat-killed LR), and 4) T3 (CON with 0.4% heat-killed LR). Each treatment had six pens with four pigs (6 replicates per treatment) in a randomized completely block design. The heat-killed LR used in this study contained 1 × 10⁹ FU/g of LR in a commercial product. Pigs were fed each treatment for four weeks using a two-phase feeding program to measure growth performance and frequency of diarrhea. During the last week of this study, all diets contained 0.2% chromic oxide as an indigestible marker. Fecal sampling was performed through rectal palpation for the consecutive three days after the four adaptation days to measure apparent total tract digestibility (ATTD) of dry matter, crude protein, and gross energy (GE). Blood sampling was also performed on day 1, 3, 7, and 14 after weaning to measure immune responses such as serum tumor necrosis factor-α (TNF-α), transforming growth factor-β1 (TGF-β1), C-reactive protein (CRP), and cortisol. The heat-killed LR increased (p < 0.05) growth rate, feed efficiency, and ATTD of GE for overall experimental period compared with CON, but reduced (p < 0.05) post-weaning diarrhea. In addition, pigs fed diets contained heat-killed had lower concentrations of serum TNF-α (d 7; p < 0.05), TGF-β1 (d 7; p < 0.10), and cortisol (d 3 and 7; p < 0.05) than pigs fed CON. In conclusion, dietary heat-killed LR improved growth rate, modified immune responses of weaned pigs, and alleviated post-weaning diarrhea.

• Journal of the Korea Institute of Building Construction
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• v.21 no.5
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• pp.483-493
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• 2021

Urban overcrowding has created an explosive supply and demand for high-rise buildings. High-rise buildings are contributing to enhancing the image of the city by serving as focal points, but due to the stack effect, malfunction of elevator doors, difficulties in opening and closing the doors and windows of the outer wall, smoke and odors spreading to the upper floors, noise, energy loss, fire and pollutants have been causing various unexpected problems such as rapid spread of fire. This study classified high-rise buildings according to their vertical zoning, analyzed the causes of and solutions to the stack effect, and derived design and construction methods. Through the initial plan to block the outside air and securing airtightness through precise construction, we sought ways to secure the airtightness inside and outside the building by actively blocking the airflow from the lower floors. In addition, the facility solution can be a measure to reduce the specific phenomena caused by the stack effect, but it should only be applied to the minimum extent because the potential for secondary damage is high. This study emphasized the need for systematic stack effect management by suggesting design and construction measures for each vertical zoning of the causes and countermeasures of the stack effect. It is expected that this study will be helpful not only for design and construction, but also for building maintenance.

• Journal of IKEEE
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• v.26 no.3
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• pp.515-519
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• 2022

In this paper, we propose the development of a high-sensitivity entry-level nuclide analysis module. The proposed measurement sensor module consists of an electronic driving circuit for nuclide analysis resolution, prototype production with nuclide analysis function, and GUI development applied to prototypes. The electronic part driving circuit for nuclide analysis resolution is divided into nuclide analysis resolution process by the electronic part driving circuit block diagram, MCU circuit design used for radiation measurement, and PC program design for Spectrum acquisition. Prototyping with nuclide analysis function is made by adding a 128×128 pixel OLED display, three buttons for operation, a Li-ion battery, and a USB-C type port for charging the battery. The GUI development department applied to the prototype develops the screen composition such as the current time, elapsed measurement time, total count, and nuclide Spectrum. To evaluate the performance of the proposed measurement sensor module, an expert witness test was conducted. As a result of the test, it was confirmed that the calculated result by applying the resolution formula to the Spectrum (FWHM@662keV) obtained using the Cs-137 standard source in the nuclide analysis device had a resolution of 17.77%. Therefore, it was confirmed that the nuclide analysis resolution method proposed in this paper produces improved performance while being cheaper than the existing commercial nuclide analysis module.

• Applied Chemistry for Engineering
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• v.33 no.1
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• pp.50-57
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• 2022

Ti-In-Zn-O (TIZO)/Ag/TIZO multilayer transparent electrodes were prepared on glass substrates at room temperature using RF/DC magnetron sputtering. Obtained multilayer structure comprising TIZO/Ag/TIZO (10 nm/10 nm/40 nm) with the total thickness of 60 nm showed a transmittance of 86.5% at 650 nm and a sheet resistance of 8.1 Ω/□. The multilayer films were expected to be applicable for use in energy-saving smart window based on polymer-dispersed liquid crystal (PDLC) because of their transmittance properties to effectively block infrared rays (heat rays). We investigated the effects of the content ratio of prepolymer, the thickness of the PDLC coating layer, and the ultraviolet (UV) light intensity on electro-optical properties, and the surface morphology of polyester acrylate-based PDLC systems using new TIZO/Ag/TIZO transparent conducting electrodes. A PDLC cell with a thickness of 15 ㎛ PDLC layer photocured at an UV intensity of 1.5 mW/cm² exhibited good driving voltage, favorable on-state transmittance, and excellent off-haze. The LC droplets formed on the surface of the polymer matrix of the PDLC composite had a size range of 1 to 3 ㎛ capable of efficiently scattering incident light. Also, the PDLC-based smart window manufactured using TIZO/Ag/TIZO multi-layered transparent electrodes in this study exhibited a light brown, which will have an advantage in terms of aesthetics.