• Title/Summary/Keyword: Reduced scale test

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Seismic Capacity Evaluation of Existing Medium-and low-rise R/C Frame Retrofitted by H-section Steel Frame with Elastic Pad Based on Pseudo-dynamic testing (유사동적실험에 의한 탄성패드 접합 H형 철골프레임공법으로 보강 된 기존 중·저층 R/C 골조의 내진성능 평가)

  • Kim, Jin-Seon;Lee, Kang-Seok
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.25 no.4
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    • pp.83-91
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    • 2021
  • In this study, to improve the connection performance between the existing reinforced concrete (R/C) frame and the strengthening member, we proposed a new H-section steel frame with elastic pad (HSFEP) system for seismic rehabilitation of existing medium-to-low-rise reinforced concrete (R/C) buildings. This HSFEP strengthening system exhibits an excellent connection performance because an elastic pad is installed between the existing structure and reinforcing frame. The method shows a strength design approach implemented via retrofitting, to easily increase the ultimate lateral load capacity of R/C buildings lacking seismic data, which exhibit shear failure mechanism. Two full-size two-story R/C frame specimens were designed based on an existing R/C building in Korea lacking seismic data, and then strengthened using the HSFEP system; thus, one control specimen and one specimen strengthened with the HSFEP system were used. Pseudodynamic tests were conducted to verify the effects of seismic retrofitting, and the earthquake response behavior with use of the proposed method, in terms of the maximum response strength, response displacement, and degree of earthquake damage compared with the control R/C frame. Test results revealed that the proposed HSFEP strengthening method, internally applied to the R/C frame, effectively increased the lateral ultimate strength, resulting in reduced response displacement of R/C structures under large scale earthquake conditions.

A Study on the Vibration Characteristics of Attitude Maneuvering of Satellite (위성의 자세기동에 따른 진동특성에 관한 연구)

  • Pyeon, Bong-Do;Bae, Jae-Sung;Kim, Jong-Hyuk;Park, Jung-Sun
    • Journal of Aerospace System Engineering
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    • v.13 no.3
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    • pp.23-31
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    • 2019
  • The design requirements of modern satellites vary depending on the purpose of operation. Like conventional medium and large-scale satellites, small satellites which operate on low orbit may also serve military purposes. As a result, there is increased demand for high-resolution photos and videos and multi-target observation becomes important. The most important design parameter for multi-target observation is the satellites' maneuverability. For increased maneuverability, the miniaturization is required to increase the stiffness of the satellite as this decreases the mass moment of inertia of the satellite. In the case of a solar panel having relatively low stiffness compared to the satellites' body, vibrations are generated when the attitude maneuver is performed, which greatly influences the image acquisition. For verification of such vibrational characteristics, the satellites is modeled as a reduced model, and experimental zig for simulating attitude maneuver is introduced. A rigidity simulator for simulating the stiffness of the satellite is also proposed. Additionally, the objective of the experimental method is to simulate the maneuvering angle of the satellite based on the winding length of the wire using a step motor, and to experimentally verify the vibration characteristics of the satellite body and the solar panel generated during the maneuvering test.

The Clinical Effect of School Sand Play Group Counseling on Child Emotion and Behavior (학교모래놀이 집단상담이 아동의 정서, 행동에 미치는 임상효과)

  • Kwak, Hyeon Jeong;An, Un Kyoung;Han, Kil Ja;Lim, Myung Ho
    • The Journal of the Korea Contents Association
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    • v.18 no.12
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    • pp.54-61
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    • 2018
  • The study was to identify the clinical effects of school sandplay group counseling on the emotions and behavior of elementary school students for the first time in Korea. The method of survey is to consult 113 students in the 4th - 6th grade of ${\bigcirc}{\bigcirc}$ elementary school for 10 weeks from March to July 2015. The small group consisted of 10 to 16 children, with one principal counselor and three or four assistant counselors participating, with 40 minutes of treatment, and a total of 12 follow-up sessions, including the Baseline assessment and treatment sessions. It was conducted to 56 male(49.6%) and 57 female(50.4%) students with questionnaires for their sex and age, assessing KCYP results at the point of baseline and post-therapeutic condition. A comparison of the clinical and detailed assessment scale scores of KCYP before and after 12 weeks of Sandplay resulted in a significant effects in improved and reduced symptoms depression of elementary school students after the school sandplay group counseling. School sandplay group counseling is thought to help elementary school students emotional problems and self-esteem.

A Study on the Output and Reliability Characteristics of Ultra Barrier Film PV Module (고분자 보호 필름을 적용한 태양광 모듈의 출력 및 신뢰성에 관한 연구)

  • Lim, Jong Rok;Shin, Woo Gyun;Yoon, Hee Sang;Kim, Yong Sung;Ju, Young-Chul;Ko, Suk-Whan;Kang, Gi-Hwan;Hwang, Hye-Mi*
    • Journal of the Korean Solar Energy Society
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    • v.39 no.5
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    • pp.1-10
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    • 2019
  • Recently, the installation capacity of PV (photovoltaic) systems has been increasing not only field installation but also floating PV, farm land, BIPV/BAPV. For this reason, the new design and materials of PV module are needed. In particular, in order to apply a PV system to a building, lightweight of the PV module is essential. PV modules made of generally used texturing glass are excellent in output and reliability, but there is a limit to the weight that can be reduced. For the lightweight of the PV module, it necessary to use a film instead of a glass. However, the application of film rather than a glass may cause various problems such as decrease in photocurrent by decrease in transmittance and a increase of CTM (cell to module) loss, a degradation of the reliability, and so on. In this paper, PV modules using Ultra barrier film, which is recently a lot of interest as a substitute for a glass, its characteristic analysis and reliability test were conducted. The transmittance and UV characteristics of each material were verified, and the output of the fabricated 1 cell PV module was measured. In addition, 24 cell PV modules were fabricated at the lab-scale and its reliability tests were conducted. As a result of the experiment, the reliability characteristics of the ultra barrier film PV module were excellent, and it was confirmed that it could be used as the front material of the PV module instead of glass

An Experimental Study on Ground Reinforcement Effect of Concrete and Expansion Mat for Prevention of Buried Pipe Damage (지중매설관 손상 방지를 위한 콘크리트매트와 팽창매트의 지반보강효과에 관한 실험적 연구)

  • Park, Jeong-Jun;Shin, Heesoo;Yuu, Jungjo;Hong, Gigwon
    • Journal of the Korean Geosynthetics Society
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    • v.18 no.1
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    • pp.91-101
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    • 2019
  • Recently, small-scale excavation like ground cavity restoration and buried pipe replacement works are being carried out in urban area, in order to improve living convenience. This paper describes experiment results on the ground reinforcement method that can reduce the buried pipe damage, when the differential settlement occurred due to poor compaction of ground below the buried pipe. Plate load tests were conducted to evaluate a reinforcement effect of ground using concrete mat and expansion mat in the ground below the buried pipe. The results showed that the stress reduction ratio by concrete mat and expansion mat according to the surcharge load was about 46%~48% and 39%~42%, respectively. Therefore, the differential settlement of the buried pipe and the ground deformation below the buried pipes were reduced by the reinforcement effect of the concrete mat and expansion mat. This means that it is possible to prevent a buried pipe damage due to underground cavity and ground subsidence, if concrete mat and expansion mat are reinforced in the ground below the buried pipe or on the ground between the buried pipes.

The Effect of Home Rehabilitation Exercise Program of Home Stayed Chronic Hemiplegic Stroke Patients (재가 만성 뇌졸중 편마비 환자의 가정 재활운동 프로그램의 효과)

  • Roh Kook Hee
    • Journal of Korean Public Health Nursing
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    • v.16 no.1
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    • pp.77-94
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    • 2002
  • This study was a quasi-experimental study of nonequivalent control group pretest- posttest design to investigate the effect of home rehabilitation exercise program on the physical and psychological functions of home stayed chronic hemiplegic stroke patients. The data were collected during the period of May 20th to August 15th, 200l. The subjects for this study were 40 hemiplegic stroke patients with the experimental group consisting of 19 patients and the control group being composed of 21 patients. The patients selected for this study were: (a)living in J city who had been diagnosed with stroke and at home after being discharged from the hospital, (b) suffering from stroke for 6 months to 5 years, (c) without recognition disorder with the MMSE-K(Mini-Mental State Examination-K)score above 25, (d) below 2 on the modified Ashworth scale, (e)free from heart and pulmonary disease, (f)able to walk beyond 15 minutes for themselves, (g) not taking regular exercises. The program for the experimental group provided 8 weeks' home rehabilitation exercise, two times of group education during the first week and individual education and supportive care after the second week through home visiting and telephoning more than once a week. The amount of time spent on rehabilitation exercise by the experimental group was 35 to 50 minutes a day, three times a week. In order to understand the effects of experiment the two groups were compared and verified by measuring the physical and psychological functions of both groups. The data were analysed by $\chi^{2}-test$, paired t-test and unpaired t-test and ANCOVA through SAS/PC program. The results of the study were as follows: 1. In terms of physical variables: grip strength. lower extremity muscle strength, walking time, ADL and serum lipid levels 1) There was no significant difference in the unaffected and affected grip strength between the two groups, even though the unaffected and affected grip strength was more improved in the experimental group than in the control group. 2) There was no significant difference in the unaffected lower extremity muscle strength between the two groups, even though the unaffected lower extremity muscle strength was more improved in the experimental group than in the control group. There was no significant difference either in the affected lower extremity muscle strength between the two groups, even though the affected lower extremity muscle strength was more improved in the experimental group than in the control group. 3) There was significant difference in walking time between the two groups. Walking time was significantly reduced in the experimental group whereas it increased in the control group. 4) There was significant difference in ADL score between the two groups. ADL score was significantly increased in the experimental group, but it significantly decreased in the control group. 5) There was significant difference in serum total cholesterol level between the two groups. After experiment the serum T-C level became lower in the experimental group whereas it became sigficantly higher in the control group. 2. In terms of psychological variables: depression and self-esteem 1) There was no significant difference in the depression between the two groups, even though the depression showed constant in the experimental group, but it showed a significant increase in the control group. 2) There was no significant difference in the self-esteem between the two groups, even though the self-esteem showed some increase in the experimental group, but it significant decrease in the control group. As shown above, the results of 8 weeks' home rehabilitation exercise program for chronic hemiplegic stroke patients produced positive effects on walking time, ADL score and serum T-C level, shortening walking time, improving activities of daily living(ADL) and lowering serum total cholesterol level.

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Evaluation of the Usefulness of Virtual Reality Equipment for Relieving Patients' Anxiety during Whole-Body Bone Scan (전신 뼈 검사 환자의 불안감 해소를 위한 가상현실 장비의 유용성 평가)

  • Kim, Hae-Rin;Kim, Jung-Yul;Lee, Seung-Jae;Baek, Song-Ee;Kim, Jin-Gu;Kim, Ga-Yoon;Nam-Koong, Hyuk;Kang, Chun-Goo;Kim, Jae-Sam
    • The Korean Journal of Nuclear Medicine Technology
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    • v.26 no.1
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    • pp.27-32
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    • 2022
  • Purpose When performing a whole-body bone scan, many patients are experiencing psychological difficulties due to the close distance to the detector. Recently, in the medical field, there is a report that using virtual reality (VR) equipment can give pain relief to pediatric patients with weak concentration or patients receiving severe treatment through a distraction method. Therefore, in this paper, VR equipment was used to provide psychological stability to patients during nuclear medicine tests, and it is intended to evaluate whether it can be used in clinical practice. Materials and Methods As VR equipment, ALLIP Z6 VR (ALLIP, Korea) was used and the experiment was conducted after connecting to a mobile phone. The subjects were 30 patients who underwent whole-body bone examination from September 1, 2021 to September 30, 2021. After intravenous injection of 99mTc-HDP, 3 to 6 hours later, VR equipment was put on and whole body images were obtained. After the test, a survey was conducted, and a Likert scale of 5 points was used for psychological anxiety and satisfaction with VR equipment. Hypothesis verification and reliability of the survey were analyzed using SPSS Statistics 25 (IBM, Corp., Armonk, NY, USA). Results Anxiety about the existing whole-body bone test was 3.03±1.53, whereas that of anxiety after wearing VR equipment was 2.0±1.21, indicating that anxiety decreased to 34%. When regression analysis of the effect of the patient's concentration on VR equipment on anxiety about the test, the B value was 0.750 (P<0.01) and the t value was 6.181 (P<0.01). decreased and showed an influence of 75%. In addition, overall satisfaction with VR equipment was 3.76±1.28, and the intention to reuse was 66%. The Cronbach α value of the reliability coefficient of the questionnaire was 0.901. Conclusion When using VR equipment, patients' attention was dispersed, anxiety was reduced, and psychological stability was found. In the future, as VR equipment technology develops, it is thought that if the equipment can be miniaturized and the resolution of VR content images is increased, it can be used in various clinical settings if it provides more realistic stability to the patient.

Nutrient Recovery from Sludge Fermentation Effluent in Upflow Phosphate Crystallization Process (상향류 인 결정화공정을 이용한 슬러지 발효 유출수로 부터의 영양소 회수)

  • Ahn, Young-Ho
    • Journal of Korean Society of Environmental Engineers
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    • v.28 no.8
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    • pp.866-871
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    • 2006
  • The nutrient recovery in phosphate crystallization process was investigated by using laboratory scale uptlow reactors, adopting sequencing batch type configuration. The industrial waste lime was used as potential cation source with magnesium salt($MgCl_2$) as control. The research was focused on its successful application in a novel integrated sludge treatment process, which is comprised of a high performance fermenter followed by a crystallization reactor. In the struvite precipitation test using synthetic wastewater first, which has the similar characteristics with the real fermentation effluent, the considerable nutrient removal(about 60%) in both ammonia and phosphate was observed within $0.5{\sim}1$ hr of retention time. The results also revealed that a minor amount(<5%) of ammonia stripping naturally occurred due to the alkaline(pH 9) characteristic in feed substrate. Stripping of $CO_2$ by air did not increase the struvite precipitation rate but it led to increased ammonia removal. In the second experiment using the fermentation effluent, the optimal dosage of magnesium salt for struvite precipitation was 0.86 g Mg $g^{-1}$ P, similar to the mass ratio of the struvite. The optimal dosage of waste lime was 0.3 g $L^{-1}$, resulting in 80% of $NH_4-N$ and 41% of $PO_4-P$ removal, at about 3 hrs of retention time. In the microscopic analysis, amorphous crystals were mainly observed in the settled solids with waste lime but prism-like crystals were observed with magnesium salt. Based on mass balance analysis for an integrated sludge treatment process(fermenter followed by crystallization reactor) for full-scale application(treatment capacity Q=158,880 $m^3\;d^{-1}$), nutrient recycle loading from the crystallization reactor effluent to the main liquid stream would be significantly reduced(0.13 g N and 0.19 g P per $m^3$ of wastewater, respectively). The results of the experiment reveal therefore that the reuse of waste lime, already an industrial waste, in a nutrient recovery system has various advantages such as higher economical benefits and sustainable treatment of the industrial waste.

A Study of Family Caregiver's Burden for the Terminally III Patients (지역사회 말기질환자 가족 부담감에 관한 연구)

  • Han, Sung-Suk;Ro, You-Ja;Yang, Soo;Yoo, Yang-Sook;Kim, Sek-Il;Hwang, Hee-Hyung
    • Journal of Korean Academic Society of Home Health Care Nursing
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    • v.10 no.1
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    • pp.58-72
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    • 2003
  • The purpose of this study was to describe the perceived burden of the terminally III patients's caregiver and to analyze relationship between the perceived burden and the various demographics, illness characteristics, family relationships, and economic factor of the family & patients. The sample of 132 caregivers who care for the terminally III patients Kyung-Gi province, Seoul, Korea. The period of this study was from August to September, 2002. The perceived burden of the family caregiver was measured by the burden scale(20 items, 4 point scale) developed by Montgomery et al. (1985). The Data was analyzed using SAS-program by t-test and ANOVA. The results were as follows; 1. The mean of the family caregiver's burden score was 3.02. The score showed that caregivers perceive severe the level of burden. The hight items of the family caregiver's burden were' I feel it is painful to watch patient's diseases'(3.77). 'I feel afraid for what the future holds for my patients'(3.66), 'I feel it reduced to amount of privacy time'(3.64). 2. The caregiver's burden was significantly related to patient's gender(F=3.17, p= 0.0020), patient's job(F=2.49, p=0.0476), caregiver's age(F=4.29, p=0.0030), and caregiver's job(F=2.49, p=0.0476). 3. The caregiver's burden according to illness characteristics showed no significant difference. 4. The caregiver's burden was significantly associated with patient's family relationship (F=4.05, p=0.0041), patient's care mean period in a day(F=47.18,

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Quality Characteristics of Frozen Doraji (Platycodon grandiflorum) according to Various Blanching Treatment Conditions (블랜칭 처리 조건에 따른 동결 도라지의 품질 특성)

  • Lee, Young-Joo;Lee, Hye-Ok;Kim, Ji-Young;Kwon, Ki-Hyun;Cha, Hwan-Soo;Kim, Byeong-Sam
    • Food Science and Preservation
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    • v.18 no.5
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    • pp.661-668
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    • 2011
  • This study was conducted to devise appropriate blanching-process conditions as a means to convert Doraji, which is widely used in Korean food due to its unique fragrance and flavor, into frozen food materials for various uses. For the Hunter L values representing the brightness transformation among the surface color and gloss changes that were observed in Doraji before and after freezing, and after Doraji went through a blanching process, the specimen that went through a blanching process at $80^{\circ}C$ showed a significantly higher value compared to another specimen processed at a higher temperature, and the first specimen's value also rose after freezing. Meanwhile, for the hardness values, they declined more as the blanching temperature became higher and as the processing time became longer. For the number of total counts and the number of coliform groups, the number of total counts at $3.75{\times}10^5$ and $1.25{\times}10^5$ cfu/g before the blanching process was reduced into the approximately 2-3 log scale, and no coliform group was detected after the blanching process. As for the peroxidase activity, its activation was decreased by the blanching process, and more than 89% of the peroxidase became inactivated in all the specimens that went through the blanching process. The sensory characteristics of the frozen-thawed Doraji by test group showed the radish leaves blanched at $90^{\circ}C$ for 1 min to be the most highly evaluated in terms of the overall preference level (p<0.05).