• Title/Summary/Keyword: Dynamic Method

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Rheological Properties of Heat-Induced Gels of Surimi from Acid and Alkali Process (산 및 알칼리 공정으로 조제한 수리미 가열 겔의 물성 특성)

  • Choi Young Joon;Park Joo Dong;Kim Jin Soo;Cho Young Jae;Park Jae W.
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.35 no.4
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    • pp.309-314
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    • 2002
  • Rhtological properties of surimi gel from white fishes by acid (acid surimi) and alkali (alkali surmi) process and effect of chemicals on gelation were investigated by punch and dynamic tests. The breaking force and deformation values of heat-induced gel of acid surimi were less than their values of alkali and conventional surimi gel, and whiteness was greatly decreased, Gel point of acid surimi was decreased but it of alkali surimi was increased with increasing moisture content in the range of 80 to $85\%$. Storage modulus of acid surimi was the highest vaule in pH 6.8, but that of alkali surimi showed high value at neutral and slightly alkali pH. Propylene glycol increased storage modulus in $20\~50^{\circ}C$, hut urea and 2-mercaptoethanol suppressed it. Potassium bromide improved storage modulus in $20~80^{\circ}C$, The results suggest that alkai process is used for making surimi instead of conventional method.

Seismic Fragility Analysis by Key Components of a Two-pylon Concrete Cable-stayed Bridge (2주탑 콘크리트 사장교의 주요 부재 지진 취약도 분석)

  • Shin, Yeon-Woo;Hong, Ki-Nam;Kwon, Yong-Min;Yeon, Yeong-Mo
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.24 no.4
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    • pp.26-37
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    • 2020
  • This study intends to present a fragility analysis method suitable for concrete cable-stayed bridges by performing an analysis reflecting design criteria and material characteristics from the results of inelastic time-history analysis. In order to obtain the fragility curve of the cable-stayed bridge, the limit state of the main component of the cable-stayed bridge is determined, and the damage state is classified by comparing it with the response value based on inelastic time history analysis. The seismic fragility curve of the cable-stayed bridge was made by obtaining the probability of damage to PGA that the dynamic response of the vulnerable parts to input ground motion would exceed the limit state of each structural member. According to the pylon's fragility curve, the probability of moderate damage at 0.5g is 32% for the longitudinal direction, while 7% for the transversal direction, indicating that the probability of damage in the longitudinal direction is higher in the same PGA than in the transversal direction. The seismic fragility curve of the connections showed a very high probability of damage, meaning that damage to the connections caused by earthquakes is very sensitive compared to damage to the pylon and cables. The cable's seismic fragility curve also showed that the probability of complete damage state after moderate damage state gradually decreased, resulting in less than 30% probability of complete damage at 2.0g.

A Study on Mapping 3-D River Boundary Using the Spatial Information Datasets (공간정보를 이용한 3차원 하천 경계선 매핑에 관한 연구)

  • Choung, Yun-Jae;Park, Hyen-Cheol;Jo, Myung-Hee
    • Journal of the Korean Association of Geographic Information Studies
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    • v.15 no.1
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    • pp.87-98
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    • 2012
  • A river boundary is defined as the intersection between a main stream of a river and the land. Mapping of the river boundary is important for the protection of the properties in river areas, the prevention of flooding and the monitoring of the topographic changes in river areas. However, the utilization of the ground surveying technologies is not efficient for the mapping of the river boundary due to the irregular surfaces of river zones and the dynamic changes of water level of a river stream. Recently, the spatial information data sets such as the airborne LiDAR and aerial images are widely used for coastal mapping due to the acquisition of the topographic information without human accessibility. Due to these advantages, this research proposes a semi-automatic method for mapping of the river boundary using the spatial information data set such as the airborne LiDAR and the aerial photographs. Multiple image processing technologies such as the image segmentation algorithm and the edge detection algorithm are applied for the generation of the 3D river boundary using the aerial photographs and airborne topographic LiDAR data. Check points determined by the experienced expert are used for the measurement of the horizontal and vertical accuracy of the generated 3D river boundary. Statistical results show that the generated river boundary has a high accuracy in horizontal and vertical direction.

A Study of the Anxiety Levels of Hospitalized Psychiatric Patients in Terms of Length of Hospitalization (정신과 입원환자의 입원기간에 따른 불안정도에 관한 연구)

  • 김윤희
    • Journal of Korean Academy of Nursing
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    • v.11 no.1
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    • pp.45-63
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    • 1981
  • This study was done to determine the relationship between the anxiety levels of hospitalized psychiatric patients and various influencing variables. The purpose of this study was to determine factors that may help hospitalized psychiatric patients to experience lower levels of anxiety in relation to changing situations and provide the basic data for a dynamic approach which is important in the field of modern psychiatric nursing that understands and analyses the meaning of patients behavior. The anxiety may produce stress, which is a common experience among all human beings. Patients may merely feel uncomfortable in the state of mild anxiety, however, the severe state could be an obstacle to treatment and recovery from disease. The anxiety of the psychiatric patient is a factor which greatly influencing the patient's behavior, so his disorderd behavior is an expression of defence or pathologically fixed behavior. According the psychiatric patient's anxiety at the time of admission is the concern of the health team. The nurse's special concern has to do with understanding and supporting the patient and meeting his individual needs by frequent close contact during the entire hospitalization period, compared to other teamembers the nurse's responsibility in this regard is greated. So this study emphasizes the necessity of creating conditions these, but above all the psychiatric nurse should create a therapeutic environment by not only regarding the patient's behavior or symptoms but understanding the meaning of them. The subjects of this study were 57 psychiatric patients selected from the K neuropsychiatric hospital located in Kunsan city. Data were collected twice from the same patients within a 24 hour period after admission and 10 days after admission. (September 18th to November 8th, 1980). The data collected method was through direct interview, and the interview time was 20 minutes for each patient. Data analysis included Item Analysis & Internal Consistency Reliability Tests, Percentages, t-test, analysis of variance and stepwise multiple regression analysis. The findings of this study were as follows. A. Test of Hypothesis a. Hypothesis 1 :“The anxiety level of psychiatric patients within 24 hours after admission will be higher than those of the same patients 10 days after admission,”was accepted. (t = 3. 15 ; p < 0.005) b. Hypothesi 2:“The more the number of admissions the higher the level of anxiety related to two categories”, was accepted. (affective anxiety: F = 5.50, p < 0.005, Somatic anxiety: F = 9.12, p <.

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Science High School Students' Shift in Scientific Practice and Perception Through the R&E Participation: on the Perspective of Legitimate Peripheral Participation in the Community of Practice (과학고등학교 학생들이 R&E 참여 과정에서 드러내는 과학적 실행 및 인식 변화 -실행공동체 내에서의 합법적 주변 참여의 관점에서-)

  • Lee, Minjoo;Kim, Heui-Baik
    • Journal of The Korean Association For Science Education
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    • v.36 no.3
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    • pp.371-387
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    • 2016
  • Learning at the elbow of scientist is a well-known educational approach to improve students' understanding of science and scientific practice. This study, in the perspective of legitimate peripheral participation in a community of practice, explores how students' scientific practice and perception could be shifted through R&E program with the development of participation. Data from participant observation for 18 months and in-depth interviews were analyzed based on constant comparative method to extract common characteristics of students' participation and major shifts in their scientific practices and perceptions. Students' development of participation was categorized into three stages: legitimate, peripheral, and full participation. In the stage of peripheral participation, students perceived themselves as mere students and showed passive engagement. They just followed the directions of researchers and didn't know what they should be doing. But through continuous participation, students showed enhanced engagement like voluntary article reading, role assignments, and establishing norms in a community of practice with the reference of scientists'. In this stage of transitional participation, students also showed a deepened perception on everyday life of scientist and the community of scientist. And finally in the stage of full participation, students showed responsibility and ownership on research and continuous efforts to refine their research. They recognized themselves as beginning scientists. With these findings, this paper highlighted the dynamic processes of students' development of scientific practices and identity through R&E participation. It also suggests implications for research programs for education, especially for students who have already articulated a science-related career but still have only foggy notions about science.

Analysis and Measurement of the Magnetic Fields Cause by Operation of Electromotive Installations (전동력설비의 운전에 의해 발생되는 자계의 측정과 해석)

  • 이복희;길경석
    • The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.9 no.2
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    • pp.58-67
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    • 1995
  • The paper describes the variation of magnetic fields caused by the operation of induction motors. The measuring system consists of the self-integrating magnetic field sensor, amplifier, and active integrator. From the calibration experiments, the frequency bandwidth of the magnetic field measuring system ranges from 20[Hz] to 300[kHz] and sensitivity is 0.234(mV/$\mu\textrm{T}$]. The magnetic fields generated under steady state and starting operations of duction motor are recorded by the proposed measuring system, and the fast Fourier transformation(FFT) of the measured data is performed to analyze the harmonic components. A single pulsed magnetic field is strongly caused by direct starting the induction motor, and its peak value is greater than 5 times as compared with the steady state value. The long transient duration and high intensity originates from the large inductance and dynamic characteristic of the induction motor, During the steady state operation of induction motor, subharmonics of magnetic field components, which depend on the pole number of induction motor, are observed. The lower order power-line harmonics can be inferred from the voltage flicker and current ripple which are derived from the torque fluctuation of induction motor. In the case of the induction motor drived by inverter, the harmonics of magnetic field are much more than those caused by direct starting method and are found generally to increase with decreasing the driving frequency.

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The effects of PNF combined patterns training on balance ability and functional ability of hockey players (PNF 통합패턴 트레이닝이 하키선수들의 균형능력과 기능적 능력에 미치는 영향)

  • Ann, Yong Duk;Park, Jong Hang
    • Journal of Digital Convergence
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    • v.11 no.11
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    • pp.521-528
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    • 2013
  • This study was performed to examine effects of PNF combined pattern training on balance ability and functional ability of hockey players. In order to achieve this purpose, total 28 participants were separated into two group: 14 comparison group and 14 experiment group, and the experiment group performed PNF combined pattern training for 12 week, 3 times a week, 60 minutes a day. Each group was measured beforehand, after 6 week and 12 week. balance ability was measured using GOOD BALANCE system and functional ability was measured using carioca and shuttle-run test. For statistically verifying above measured values, repeated measure analysis of variance was analyzed and have following results. As the comparing results of balance ability, normal standing eye close(NSEC) was ant-post and velocity moment of experiment group showed significant differences(p<.05). And one leg right eye close(OLREC) was ant-post, med-lat and velocity moment of experiment group showed significant differences (p<.05). Also, dynamic balance ability was ant-post and velocity moment of experiment groups showed significant differences(p<.05). As the comparing results of functional ability, shuttle-run of experiment group sowed significant differences(p<.05). From above results, balance ability of hockey players was shown to be improved through symmetric training of PNF combined pattern applied to hockey players, and it can be considered that this is actively recommended for training method to improve athletic performance of hockey players.

The Effects of Upper and Lower Limb Coordinated Exercise in One Leg Support or non Support on Gait Ability in Chronic Stroke Patients (한 발 지지 유무에 따른 상하지 협응운동이 만성 뇌졸중 환자의 보행능력에 미치는 영향)

  • Kuk, Eun-Ju
    • Journal of Digital Convergence
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    • v.11 no.7
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    • pp.281-288
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    • 2013
  • The purpose of this study was to identify the effects of upper and lower limb coordinated exercise for gait ability in stroke patients. Upper and lower limb coordinated exercise method was conducted in two different groups; one is an one leg support group and the other is a non support group. In this study, 14 patients were participated. One leg support group was applied to 7 patients, and non support group was applied to 7 patients. Both group carried out 3 times a week for 30 minutes during 4 weeks. Data were analyzed statistically via Repeated two-way ANOVA, Mann-Whitney U test, and Friedman test. The results of the measurement analysis were summarized as follows: 1. There were significant differences in 10MWT among 2 groups after intervention(p<.05). 2. There were significant differences in F8WT, FSST among 2 groups after intervention(p<.05). According to Bonferroni test, one leg support group had significant increased from pre-intervention to post-4 week. However, there were no significant differences in nonsupport group. In conclusion, improvement of gait ability in chronic stroke patients was effect to upper and lower limb coordinated exercise.

An equivalent model for the seismic analysis of high-rise shear wall apartments (고층 벽식 아파트의 지진해석을 위한 등가모델)

  • Kim, Tae-Wan;Park, Yong-Koo;Kim, Hyun-Jung;Lee, Dong-Guen
    • Journal of the Earthquake Engineering Society of Korea
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    • v.11 no.5
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    • pp.11-21
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    • 2007
  • Currently in the country, the necessity of seismic analyses is increasing due to the increase of demand and interest in seismic design. Especially, shear wall apartments are constructed mostly for a residental building so seismic analyses for the apartment are actively executed. For the seismic analysis of the shear wall apartment, it may be not efficient in time and effort to model the entire structure by a finite element mesh. Therefore, an equivalent model is needed to simulate the dynamic behavior of the structure by decreasing the number of degrees of freedom. In this study, a method to form an equivalent model that is simple and easy to use was proposed utilizing effective mass coefficient that is highly correlated to mode shape of the structure. This equivalent model was obtained by replacing a shear wall structure with an equivalent frame structure having beams and columns. This model can be used very effectively when excessive seismic analyses are necessary in a short period because it can be operated in any commercial program and reduce the analysis time. Also, it can model floor slabs so it can represent the actual behavior of shear wall apartments. Furthermore, it is very excellent since it can represent the asymmetry of the structure.

Estimation of Shear Wave Velocity of Earth Dam Materials Using Artificial Blasting Vibration Test (인공발파진동실험을 이용한 흙댐 축조재료의 전단파속도 산정)

  • Ha, Ik-Soo;Kim, Nam-Ryong;Lim, Jeong-Yeul
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.33 no.2
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    • pp.619-629
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    • 2013
  • The objective of this study is to estimate shear wave velocity of earth dam materials using artificially generated vibration from blasting events and to verify its applicability. In this study, the artificial blasting and vibration monitoring were carried out at the site adjacent to Seongdeok dam, which is the first blasting test for an existing dam in Korea. The vibrations were induced by 4 different types of blasting with various depths of blasting boreholes and explosive charge weights. During the tests, the acceleration time histories were recorded at the bedrock adjacent to the explosion and the crest of the dam. From frequency analyses of acceleration histories measured at the crest, the fundamental frequency of the target dam could be evaluated. Numerical analyses varying shear moduli of earth fill zone were carried out using the acceleration histories measured at the bedrock as input ground motions. From the comparison between the fundamental frequencies calculated by numerical analyses and measured records, the shear wave velocities with depth, which are closely related to shear moduli, could be determined. It is found that the effect of different blasting types on shear wave velocity estimation for the target dam materials is negligible and the shear wave velocity can be consistently evaluated. Furthermore, comparing the shear wave velocity with the previous researchers' empirical relationships, the applicability of suggested method is verified. Therefore, in case that the earthquake record is not available, the shear wave velocity of earth dam materials can be reasonably evaluated if blasting vibration test is allowed at the site adjacent to the dam.