• Title/Summary/Keyword: on-site testing

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VSimulators: A New UK-based Immersive Experimental Facility for Studying Occupant Response to Wind-induced Motion of Tall Buildings

  • Antony Darby;James Brownjohn;Erfan Shahabpoor;Kaveh Heshmati
    • International Journal of High-Rise Buildings
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    • v.11 no.4
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    • pp.347-362
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    • 2022
  • Current vibration serviceability assessment criteria for wind-induced vibrations in tall buildings are based largely on human 'perception' thresholds which are shown not to be directly translatable to human 'acceptability' of vibrations. There is also a considerable debate about both the metrics and criteria for vibration acceptability, such as frequency of occurrence or peak vs mean vibration, and how these might vary with the nature of the vibration. Furthermore, the design criteria are necessarily simplified for ease of application so cannot account for a range of environmental, situational and human factors that may enhance or diminish the impact of vibrations on serviceability. The dual-site VSimulators facility was created specifically to provide an experimental platform to address gaps in understanding of human response to building vibration. This paper considers how VSimulators can be used to inform general design guidance and support design of specific buildings for habitability, in terms of vibration, which allow engineers and clients to make informed decisions with regard to sustainable design, in terms of energy and financial cost. This paper first provides a brief overview of current vibration serviceability assessment guidelines, and the current understanding and limitations of occupants' acceptability of wind-induced motion in tall buildings. It then describes how the dual-site VSimulators facility at the Universities of Bath and Exeter can be used to assess the effects of motion and environment on human comfort, wellbeing and productivity with examples of how the facility capabilities have been used to provide new, human experience based experimental research approaches.

An Experimental Study on Establishing Criteria of Gripping Work in Construction Site (건설 현장 악력 작업안전 기준 설정에 관한 실험적 연구)

  • 손기상;이인홍;최만진;안병준
    • Journal of the Korean Society of Safety
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    • v.10 no.3
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    • pp.81-95
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    • 1995
  • Now, safety assurance in construction sites should be accomplished by its own organization rather than control of the code or government. It is believed that the safety assurance can be considerably improved by a lecture or an education using the existing theories or literatures up to now, but it is thought that fundamental safety assurance we not able to be accomplished without developing safety devices '||'&'||' equipment or taking fundamental measures, based on the result analyzed from workers behaviors. There are various behaviors of the workers showed in construction site, but only tests for hammerusing works such as form, re-bar, stone workers directly related to the grip strength are mainly performed, investigated and measured here for the study. The above works are similar to power grip, 7th picture on seven items which are categorized for hand grip types(Ammermin 1956 ; Jones ; Kobrick 1958). Measurements of grip strength are commonly taken in anthropometric surveys. They are easy to administer but unfortunately it is rather dubious whether they yield any data that are of interest to the engineer. Very fewer controls of tools are grasped and squeesed studies showed very little overall correlation between grip strength and other measures of bodily strength (Laubach, Kromer, and Thordsen 1972), but hammer-using work which is practically progressed in construction site are mainly influenced with grip strength. According to the investigation on work measurement, it is shown that 77% of form worker are using hammer to be related to grip strength. In this study, it is particularly noticed that wearing safety gloves in construction site is required for workers safety but 20% difference between grip strength with safety gloves and without ones are commonly neglected in the site(Fig. 1). Nevertheless, safety operation with consideration of the above 20% difference is not considered in the construction site. Factors of age, kinds of work, working time, with or without safety gloves are in vestigated '||'&'||' collected at the sites for this study. Test, not at each working hour but at 14 : 00 when the almost all of the workers think the most tired, resulting from the questionaires, also when it is shown on the research report has been performed and compared for main kinds of works : form '||'&'||' re-bar work. Tests were performed with both left SE rightand of the workers simultaneously in construction site using Rand Dynamometer(Model 78010, Lafayette Instrument Co., Indiana, U.S.A) by reading grip strength on the gauge while they are pulling, and then by interviewing on their ages, works, experiences and etc., directly. The above tests have been performed for the dates of 15th march-26th May '95 with consideration of site condition. And even if various factors of ambient temperature on the testing date, working condition, individual worker's habit and worker's condition of the previous ate are concerned with the study. Those are considered as constants in this study. Samples are formwork 53, rebar 62, electrician 5, plumber 4, welding 1 from D construction Co., Ltd, ; formwork 12, re-bar 5, electrician 2, from S construction Co., Ltd, , formwork 78, re-bar 18, plumber 31, electrician 13, labor 48, plumber 31, plasterer 15, concrete placer 6, water proof worker 3, maisony 5 from B construction Co., Ltd. As In the previously mentioned, main aspect to be investigated in this study will be from '||'&'||' re-bar work because grip strength will be directly applied to these two kinds of works ; form '||'&'||' re-bar work, eventhough there are total 405 samples taken. It is thought that a frequency of accident occurrence will be mainly two work postures "looking up '||'&'||' looking down" to be mainly sorted, but this factor is not clarified in this study because It will be needed a lot of work more. Tests has been done at possible large scale of horizontally work-extended sites within one hour in order to prevent or decrease errors '||'&'||' discrepancies from time lag of the test. Additionally, the statistical package computer program SPSS PC+has been used for the study.

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Determination of Mean Shear Wave Velocity to the Depth of 30m Based on Shallow Shear Wave Velocity Profile (얕은 심도 전단파속도 분포를 이용한 30m 심도 평균 전단파속도의 결정)

  • Sun, Chang-Guk;Chung, Choong-Ki;Kim, Dong-Soo
    • Journal of the Earthquake Engineering Society of Korea
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    • v.11 no.1 s.53
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    • pp.45-57
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    • 2007
  • The mean shear wave velocity to the depth of 30 m (Vs30) derived from the western Vs is the current site classification criterion for determining the design seismic ground motion taking into account the site amplification potential. In order to evaluate the Vs30 at a site, a shear wave velocity (Vs) Profile extending to at least 30 m in depth must be acquired from in-situ seismic test. In many cases, however, the resultant depth of the Vs profile may not extend to 30 m, owing to the unfavorable field condition and the limitation of adopted testing techniques. In this study, the Vs30 and the mean shear wave velocity to a depth shallower, than 30 m (VsDs) were computed from the Vs profiles more than 30 m in depth obtained by performing various seismic tests at total 72 sites in Korea, and a correlation between Vs30 and VsDs was drawn based on the computed mean Vs data. In addition, a method for extrapolating the Vs profile from shallow depth to 30 m was developed by building a shape curve based on the average data of all Vs profiles. For evaluating the Vs30 from the shallow Vs profiles, both the methods using VsDs and shape curve result in less bias than the simplest method of extending the lowermost Vs equally to 30 m in depth, and are usefully applicable particularly in the cases of the Vs profiles extending to at least 10 m in depth.

A Study on the Improvement Plans of Maintenance Monitoring in Tunnel Structure (터널구조물 유지관리계측의 개선방안 연구)

  • Woo, Jong-Tae
    • Journal of the Society of Disaster Information
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    • v.16 no.1
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    • pp.10-20
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    • 2020
  • Purpose: Analyze the results of on-site inspection of the tunnel structure maintenance management monitoring and suggest improvement plans. Method: We investigate and analyze the problems of various items on maintenance monitoring of tunnel structure of 14 subway lines of Seoul subway in downtown area. Result: The maintenance monitoring items, measurement quantity and installation location are classified into open tunnel and excavation tunnel and improvement plans are suggested respectively. Various durability criteria of the measuring instruments were examined, and durability confirmation method suggested improvement measures such as approval, inspection, inspection and testing, calibration of monitoring sensors. Conclusion: Applying the improvement measures of the tunnel structure maintenance monitoring to the construction site will increase the efficiency of the maintenance monitoring and contribute to the development of construction monitoring technology.

Field testing and numerical modeling of a low-fill box culvert under a flexible pavement subjected to traffic loading

  • Acharya, Raju;Han, Jie;Parsons, Robert L.;Brennan, James J.
    • Geomechanics and Engineering
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    • v.11 no.5
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    • pp.625-638
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    • 2016
  • This paper presents field study and numerical modeling results for a single-cell low-fill concrete box culvert under a flexible pavement subjected to traffic loading. The culvert in the field test was instrumented with displacement transducers to capture the deformations resulting from different combinations of static and traffic loads. A low-boy truck with a known axle configuration and loads was used to apply seven static load combinations and traffic loads at different speeds. Deflections under the culvert roof were measured during loading. Soil and pavement samples were obtained by drilling operation on the test site. The properties of the soil and pavement layers were determined in the laboratory. A 3-D numerical model of the culvert was developed using a finite difference program FLAC3D. Linear elastic models were used for the pavement layers and soil. The numerical results with the material properties determined in the laboratory were compared with the field test results. The observed deflections in the field test were generally smaller under moving loads than static loads. The maximum deflections measured during the static and traffic loads were 0.6 mm and 0.41 mm respectively. The deflections computed by the numerical method were in good agreement with those observed in the field test. The deflection profiles obtained from the field test and the numerical simulation suggest that the traffic load acted more like a concentrated load distributed over a limited area on the culvert. Elastic models for culverts, pavement layers, and surrounding soil are appropriate for numerical modeling of box culverts under loading for load rating purposes.

Idiopathic Postganglionic Horner's Syndrome in Dogs : 3 cases (개의 특발성 절후성 Horner's syndrome 3례)

  • Kim, Se-Eun;Park, Shin-Ae;Jeong, Man-Bok;Yi, Na-Young;Kim, Won-Tae;Chae, Je-Min;Seo, Kang-Moon
    • Journal of Veterinary Clinics
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    • v.24 no.3
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    • pp.441-443
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    • 2007
  • Horner's syndrome is a group of clinical signs that results from interference with the sympathetic innervation of the globe and adnexa. Three dogs were presented with unilateral ptosis, miosis, enophthalmos and protrusion of the third eyelid. There were no other clinical signs on physical and neurological examination. On ophthalmic examination, the symptomatic eyes were diagnosed as Horner's syndrome. In order to localize the site of the lesion, pharmacological testing was performed through assessment of ocular response to the topical administration of 10% phenylephrine and clinical signs were resolved within 20 minutes. The pharmacological testing suggested that the deficit could be at the postganglionic neuron. Total resolution of clinical signs was observed within 6 months after their initial appearance without any treatment.

Development and Site Evaluation of the On-line Partial Discharge Measuring System on the 13 kV Class Stator Windings for Hydro Generator (13 kV급 수력발전기 고정자 권선용 On-line 부분방전 측정 시스템 개발 및 현장적용 평가)

  • Sun, Jong-Ho;Hwang, Don-Ha;Yun, Young-Ho;Shin, Byoung-Chol;Oh, Bong-Keun;Kang, Dong-Sik
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.55 no.4
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    • pp.189-198
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    • 2006
  • In order to improve the reliability of stator windings for hydro generators, it is necessary to detect the defective point and life assessment of the high voltage windings. Especially the on-line partial discharge (PD) test provides the ability to monitor effects, such as slot discharge, internal discharge, and end-winding discharge without interrupting generators, this method has been proven the major testing technology in high voltage rotating machines nowadays. The purpose of this paper is to describe the method of the on-line PD measurement on stator windings for hydro-generator with 13 [kV] class ceramic coupler (CC), on-line PD measuring system, terminal box, and index parameters. Also, the developed PD measuring system and 13 [kV] class CC were installed Daechung-dam generator #2. It was found that this installed sensor and system had good electrical characteristics to detect PD activity during the operating condition with its detection frequency band is between several and several tens MHz.

Analysis of the Acceleration Characteristics on the Conventional line for Korean High Speed Train- in il point of passing speed on the curve (한국형 고속전철의 기존선 주행 진동가속도 특성 분석 - 곡선 통과속도 중심으로)

  • 김영국;김석원;목진용;박찬경
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2004.05a
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    • pp.222-227
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    • 2004
  • Korean High Speed Train(KHST) has been tested on the high speed test line in Osung site, since it was developed through the G7 Project Plan in 2002. It was also tested on the conventional line such as KyongBu and Honan Line to know the possibility of increasing the limited speed for the high speed trains. This paper introduces the method to improve the speed on the conventional line with body lateral acceleration among the several considered issues and explains the parameters related to those analysis, such as the cant deficiency, the radius of curve, speed and etc. When a train pass on the curved track, the lateral accelerations of body are divided into the quasi-static and the maximum accelerations according to the UIC 518 which is the international specification for testing and approval of railway vehicles from the point of view of their dynamic behaviour, especially for safety and ride comfort. This paper shows that it is safe and comfort from the results of test when KHST runs on the conventional line with the curves and proposes that the limited speed of conventional curved line could be changed to a little higher speed if the analysises of other fields are completed.

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Bacterial profile of suction drains and the relationship thereof to surgical-site infections in prosthetic breast reconstruction

  • Yoon, Jeongmin;Chung, Jae-Ho;Hwang, Na-Hyun;Lee, Byung-Il;Park, Seung-Ha;Yoon, Eul-Sik
    • Archives of Plastic Surgery
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    • v.45 no.6
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    • pp.542-549
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    • 2018
  • Background Despite the increasing popularity of prosthetic breast reconstruction, scant data exist on the microbiological profile of drainage fluid from closed-suction drains and the relationship thereof to surgical-site infections (SSIs) in breast reconstruction surgery. This study aimed to determine whether bacteria isolated from drainage fluid were associated with the development of SSIs, and whether the bacterial profile of drainage fluid could be a clinically useful predictor of SSIs. Methods We performed a retrospective chart review of 61 women who underwent tissue expander/implant or direct-to-implant reconstructions. Patient demographics and culture studies of drainage fluid from suction drains collected on postoperative day 7 were evaluated. Results Sixteen patients (26.23%) were culture-positive, and 45 patients (73.77%) were culture-negative. The most frequently isolated bacteria were coagulase-negative staphylococci, followed by Staphylococcus aureus. SSIs were diagnosed in seven patients and were mostly resolved by systemic antibiotics; however, the tissue expander or implant was explanted in two patients. Positive culture of drainage fluid from closed-suction drains was significantly associated with the development of SSIs (P<0.05). The positive predictive value was 37.50%, and the negative predictive value was 97.78%. Conclusions To our knowledge, this study is the first to demonstrate a significant association between the microbiological profile of drainage fluid from closed-suction drains and the development of SSIs in patients with prosthetic breast reconstructions. The high negative predictive value suggests that microbial testing of drainage fluid from closed-suction drains may have clinical utility. Further prospective studies with larger sample sizes are required to confirm our findings.

Comparison between wind load by wind tunnel test and in-site measurement of long-span spatial structure

  • Liu, Hui;Qu, Wei-Lian;Li, Qiu-Sheng
    • Wind and Structures
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    • v.14 no.4
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    • pp.301-319
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    • 2011
  • The full-scale measurements are compared with the wind tunnel test results for the long-span roof latticed spatial structure of Shenzhen Citizen Center. A direct comparison of model testing results to full-scale measurements is always desirable, not only in validating the experimental data and methods but also in providing better understanding of the physics such as Reynolds numbers and scale effects. Since the quantity and location of full-scale measurements points are different from those of the wind tunnel tests taps, the weighted proper orthogonal decomposition technique is applied to the wind pressure data obtained from the wind tunnel tests to generate a time history of wind load vector, then loads acted on all the internal nodes are obtained by interpolation technique. The nodal mean wind pressure coefficients, root-mean-square of wind pressure coefficients and wind pressure power spectrum are also calculated. The time and frequency domain characteristics of full-scale measurements wind load are analyzed based on filtered data-acquisitions. In the analysis, special attention is paid to the distributions of the mean wind pressure coefficients of center part of Shenzhen Citizen Center long-span roof spatial latticed structure. Furthermore, a brief discussion about difference between the wind pressure power spectrum from the wind tunnel experiments and that from the full-scale in-site measurements is compared. The result is important fundament of wind-induced dynamic response of long-span spatial latticed structures.