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A Study on the Failure Detection and Validation of Pressurizer Level Signal in Nuclear Power Plant (원전 가압기수위신호 고장검출 및 검증에 관한연구)

  • Oh, S.H.;Kim, D.I.;Zoo, O.P.;Chung, Y.H.;Lim, C.H.;Yun, W.Y.;Kim, K.J.
    • Proceedings of the KIEE Conference
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    • 1995.11a
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    • pp.175-177
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    • 1995
  • The sensor signal validation and failure detection system must be able to detect, isolate, and identify sensor degradation as well as provide a reconstruction of the measurements. In this study, this is accomplished by combining the neural network, the Generalized Consistency Checking(GCC), and the Sequential Probability Ratio Test(SPRT) method in a decision estimator module. The GCC method is a computationally efficient system for redundant sensors, while the SPRT provides the ability to make decisions based on the degradation history of a sensor. The methodology is also extended to the detection of noise degradation. The acceptability of the proposed method is demonstration by using the simulation data in safety injection accident of nuclear power plants. The results show that the signal validation and sensor failure detection system is able to detect and isolate a bias failure and noise type failures under transient conditions. And also, the system is able to provide the validated signal by reconstructing the measurement signals in the failure conditions considered.

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A study on selection and size of Earth in application of Rammed Earth (흙다짐 적용을 위한 흙의 선정 및 입도조건에 관한 연구)

  • Hwang, Hey Zoo;Kim, Tae Hun;Yang, Jun Hyuk
    • KIEAE Journal
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    • v.9 no.2
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    • pp.65-71
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    • 2009
  • Results from tests for what mixing rate of soil and sand is proper for the rammed earth and for how much additives are optimum are as under. 1) In the test to evaluate what mixing rate of soil and sand is desirable, peptizing property and surface sticking rate are found similar in its degree, but compression strength is found most stable when the ratio of soil and sand mixing shows 30:70 which indicates the best mixing rate of soil and sand. 2) In a test to add hydrated lime, compression strength, peptizing property, and surface sticking rate are found best when the mixing rate of soil and sand shows 23:7. 3) In a test to add sea weeds, the peptizing property goes down at 75% of sea weeds input a little bit more than at 100%, but compression strength shows best at 75% which is thought to be the best rate. 4) In a drop test, more soil powder mixed, the sticking strength gets better and more sands are contained, the sticking strength gets far worse to be scattered in powder type. 5) As concluding all results mentioned in the above item, the most desirable mixing rate of soil, sand, and hydrated lime is found to be 23:7:70 for the rammed earth where compression strength, peptizing property, and surface sticking rate are best.

Pain in Animals: Anatomy, Physiology, and Behaviors

  • Youn, Dong-ho;Kim, Tae Wan;Cho, Hee-jung
    • Journal of Veterinary Clinics
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    • v.34 no.5
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    • pp.347-352
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    • 2017
  • Pain, an adaptive but unpleasant sensation, is the most common symptom of numerous diseases in humans and animals. Although animal patients express this symptom frequently, a lack of communication abilities hinders its recognition by veterinary physicians, thereby leading to unsatisfactory management of the symptom. On the other hand, pain itself has its own neurological mechanisms, regardless of the disease that causes it. Thus, a physician may need to know the mechanisms underlying pain development in order to properly manage the symptom in a particular disease. In this review, we attempt to provide a brief introduction to the anatomical, physiological, and neurological basis of pain transmission and sensation. Although most knowledge about these mechanisms comes from studies in humans and laboratory animals, it is generally applicable to pet, farm, or zoo animals. In addition, we summarize pain behavior in several pet, farm, and laboratory animals for its proper identification. This information will help to identify and manage pain, and thus improve welfare, in animals.

Earth Building Characteristic Analysis to Utilize in Architecture Plan (건축 계획적 활용을 위한 흙건축 특성분석)

  • Lee, jang-hyuk;Hwang, hey-zoo;Kim, Jeong-Gyu
    • KIEAE Journal
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    • v.7 no.4
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    • pp.3-8
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    • 2007
  • This study is aimed to apply basic data to planning earth building through analyzing characteristics of earth building. For doing it, we investigated a research paper in advanced countries(New zealand, Australia, etc.) that has been used for earth building standards for a long time, and then we corrected inadequate standards that would apply our earth building environment. As a result, we can devide earth characteristics into three parts that are materials, plan, and maintenance and repair. First, as material selection is very important factor, a general plan is possible to change in accordance with what material is selected. These methods that made mud brick, pressed earth block, rammed earth, cob have been well used during the current 30 years in earth building. Second, the plan is composed of site select and architecture plan. In architecture plan, we should consider from foundation to eaves protection, and in site selection, consider sides of the environment and the social. Third, we should always check a periodical inspection through watchful observation because earth buildings need more time and efforts in maintaining and repairing than others.

An Experimental Study on the Non-Uniform Flow Distribution in the Windbox of an Oil-Fired Boiler (유류 연소 발전용 보일러에서 공기 공급 계통의 불균일성에 관한 실험적 연구)

  • Go, Young-Gun;Kim, Young-Zoo;Choi, Sang-Min
    • Journal of the Korean Society of Combustion
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    • v.11 no.1
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    • pp.1-10
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    • 2006
  • Oil-fired power plant usually uses several burners and combustion air is supplied to each burner through the complicated duct which is called windbox. A windbox should be designed to supply combustion air to each burner uniformly but, due to the complicated duct shape, flow distribution in the windbox is unbalanced and non-uniform supplies of combustion air are induced by these unbalanced flows in the windbox. These flow patterns tend to make flame unstable, increase the formation of pollutants and lower the overall combustion efficiency. To prevent these disadvantages, flow patterns in the windbox should be investigated for the uniform flow distribution. In this study, computational simulation method was used to investigate the flow distribution in a windbox and measured the velocities at the exit of burners in a real windbox and model tests to compare with CFD results. The results show two significant flow patterns. One is that the flow rates of each burner are different from each other and this means that all burners operate in different conditions of air to fuel ratio. The other is that the flow distribution at the exit of each burner is not axi-symmetric although the burner shape is axi-symmetric. Additionally some modifications of windbox shape and installation of baffles were proposed to make the uniform flow in the windox.

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Wind Tunnel Test of a Canard Airplane

  • Chung, Jin-Deog;Cho, Ta-Hwan;Lee, Jang-Yeon;Sun, Bong-Zoo
    • Journal of Mechanical Science and Technology
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    • v.16 no.1
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    • pp.125-131
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    • 2002
  • A low speed wind tunnel test was conducted for a canard airplane model in KARI LSWT. The purpose of the presented paper is to investigate the proper testing approach to correct tare precisely and the interference effects for the canard models which has 21% of canard-to-wing area ratio. Most of tests were performed with image system installation for various elevator deflection conditions at the flexed canard incidence angles. To evaluate the effectiveness of the image system, the obtained correction quantity at an zero elevator setting condition with image system was applied to the rest of elevator deflections and compared with the acquired results for all elevator deflections with image system. Test result showed that the amount of correction quantities were strongly dependent on the elevator deflections, and the difference in aerodynamic coefficients for two approaches was gradually amplified as the elevator deflection angles increased. An adoption of the image system was strongly recommended for the higher canard-to -wing area ratio model, if a proper level of accuracy was required.

A Study on Characteristics of Insulation Breakdown by the Mixing Ratio of enhanced Dry Air and SF6 (개선된 Dry Air와 SF6의 혼합비에 따른 절연파괴 특성 연구)

  • Seok, Jeong-Hoo;Beak, Jong-Hyun;Lim, Dong-Young;Bae, Sungwoo;Kim, Ki-Chai;Park, Won-Zoo
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.30 no.3
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    • pp.86-93
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    • 2016
  • It is very desirable that a mixture gas possessing excellent insulation performance is suggested for insulation on increasing high voltage. This paper proposes a $SF_6$ mixture gas based on the factors including dielectric strength, environmental impact and economic feasibility of manufacture for the insulation in eco-friendly power equipment. A suitable-$SF_6$ content was determined to improve the dielectric strength in $N_2$ and Dry Air. The examination results of the factors revealed that a $SF_6$/Dry Air mixture gas possessing the $SF_6$ content was more appropriate than a $SF_6/N_2$ mixture gas to the eco-friendly power equipment. In addition to the selection of the suitable $SF_6$ mixture gas, insulation characteristics as a function of $SF_6$ content were described from electron-detachment mechanism.

Wear Characteristics of Multi- span Tube Due to Turbulence Excitation (다경간 전열관의 난류 가진에 의한 마모특성 연구)

  • Kim, Hyung-Jin;Sung, Bong-Zoo;Park, Chi-Yong;Ryu, Ki-Whan
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.16 no.9 s.114
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    • pp.904-911
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    • 2006
  • A modified energy method for the fretting wear of the steam generator tube is proposed to calculate the wear-out depth between the nuclear steam generator tube and its support. Estimation of fretting-wear damage typically requires a non-linear dynamic analysis with the information of the gap velocity and the flow density around the tube. This analysis is very complex and time consuming. The basic concept of the energy method is that the volume wear rate due to the fretting-wear phenomena Is related to work rate which is time rate of the product of normal contact force and sliding distance. The wearing motion is due to dynamic interaction between vibrating tube and its support structure, such as tube support plate and anti-vibration bar. It can be assumed that the absorbed work rate would come from turbulent flow energy around the vibrating tube. This study also numerically obtains the wear-out depth with various wear topologies. A new dissection method is applied to the multi-span tubes to represent the vibrational mode. It turns out that both the secondary side density and the normal gap velocity are important parameters for the fretting-wear phenomena of the steam generator tube.

Overexpression of the SPP2 gene of saccharomyces cerevisiae and production of antibodiesd to Spp2p

  • Park, Kwang-Hark;Lea, Ho-Zoo;L. Woolford;Kim, Kyung-Hoon
    • Journal of Microbiology
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    • v.33 no.3
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    • pp.201-207
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    • 1995
  • We have previously reported that SPP2 gene product of yeast Saccharomyces cerevisiae is involved in the pre-mRNA splicing. To investigate the rol ein the splicing pathway of the Spp2p protein, the SPP2 gene was overexpressed in Escherichia coli and polyclonal antibodies to Spp2p were generated from rabbits. First, a DNA fragment containing the SPP2 GENE without its promoter was subcloned into an E. coli expression vector, pKK233-3. The resulting recombinant plasmid pBQ14 contained an IPTG inducible tac promoter and the SPP2 structural gene. Overexpression of the SPP2 gene was achieved by additionof 0.1 to 1.0 mM IPTG to a logarithmic culture of E. coli JM103(pBQ14) for 90 min at 37.deg.C. Sequence of N-terminal 15 amino acids of the overproduced protein was well matched to the deduced one from the SPP2 reading frame. Then, polyclonal antibodies were generated from rabbits immunized with gel-purified SppSp protein. These antibodies reacted specifically with the Spp2p protein extracted from yeast cells expressing the SPP2 gene to a great extent. The antibodies could also block the activity of yeast splicing extracts.

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Characteristics of Optical Current Sensors by Sensor Design

  • Kim, Young-Min;Park, Jung-Hwan;Lee, Kwang-Sik;Kim, Jung-Bae;Park, Won-Zoo
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.21 no.4
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    • pp.80-87
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    • 2007
  • This paper will suggest that the 1 cross orthogonal loop type sensor improves on the orthogonal loop form sensor-head, which is available a calibration of the linear birefringence, when a fiber optic current sensor was composed. An output characteristics of the 1 cross orthogonal loop form, a general closed loop form, the orthogonal loop form are compared by the IEC(International Electrotechnical Commission) 60044-8 standard, and the state of polarization is compared with three forms. As a result, when the closed loop form was changed to the orthogonal loop form, retardation decreased 15.3[%]. When the closed loop form was changed to the 1 cross orthogonal loop type, the retardation decreased 33.8[%]. As a result of the Faraday Effect measurement, the 1 cross orthogonal loop form has the highest output characteristic and the lowest error ratio. It met the 0.5 class of the IEC 60044-8 standard. Thus, in application of the 1cross orthogonal loop form, the possibility to develop high reliability fiber optic current sensors that have a high output and stable error ratio rises is increased.