• Title/Summary/Keyword: Overload prevention

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Study on the Safety Assurance for the Temporary Structures (가설구조물 안전성 확보 방안 연구)

  • Lee, Jung Seok;Moon, Seong Oh;Youn, Ye Bin;Lim, Nam Gi;Oh, Tae Keun
    • Journal of the Korean Society of Safety
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    • v.33 no.1
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    • pp.73-80
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    • 2018
  • According to the statistics publication of KOSHA, more than half of serious accidents at the construction sites were related to the temporary works and/or the temporary structures such as scaffoldings, shores, earth retaining walls, etc. The structural failures are occurred because of the overload acting on the structures or lack of performance of the one or more members of the structures. For the prevention of the collapse accidents relating to the temporary structures at the construction sites, we have to control construction processes not to occur the overload and also to control the performance and quality of each member of the temporary structures. MOLIT has amended the "Construction Technology Promotion Act" on Jan. 7th, 2015 to ensure the structural safety of the temporary structures. According to the Act, the designers of the construction design projects should check the structural integrity of the structures including the temporary structures and the construction companies have to let 'the Relative Professionals' confirm the structural integrity of temporary structures, the shores(${\geq}5m$ high) and the scaffolds(${\geq}31m$ high), before construction. Also, MOLIT has amended the "Regulation for Construction Technology Promotion Act" on Jul. 4th, 2016 for quality management and testing of temporary equipments. According th this regulation, the construction companies and supervisors should manage and test the temporary equipments before using them. In this paper, the standard drawings of the shores(< 5 m high) and the scaffolds(< 31 m high) and the amended "Business Guideline for Quality Management of Construction Work" are presented. As the result of this study, MOLIT noticed the amended "Business Guideline for Quality Management of Construction Work" on Jul. 1st, 2017.

A Study on the Data Analysis of Fire Simulation in Underground Utility Tunnel for Digital Twin Application (디지털트윈 적용을 위한 지하공동구 화재 시뮬레이션의 데이터 분석 연구)

  • Jae-Ho Lee;Se-Hong Min
    • Journal of the Society of Disaster Information
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    • v.20 no.1
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    • pp.82-92
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    • 2024
  • Purpose: The purpose of this study is to find a solution to the massive data construction that occurs when fire simulation data is linked to augmented reality and the resulting data overload problem. Method: An experiment was conducted to set the interval between appropriate input data to improve the reliability and computational complexity of Linear Interpolation, a data estimation technology. In addition, a validity verification was conducted to confirm whether Linear Interpolation well reflected the dynamic changes of fire. Result: As a result of application to the underground common area, which is the study target building, it showed high satisfaction in improving the reliability of Interpolation and the operation processing speed of simulation when data was input at intervals of 10 m. In addition, it was verified through evaluation using MAE and R-Squared that the estimation method of fire simulation data using the Interpolation technique had high explanatory power and reliability. Conclusion: This study solved the data overload problem caused by applying digital twin technology to fire simulation through Interpolation techniques, and confirmed that fire information prediction and visualization were of great help in real-time fire prevention.

Reducing the Falling Accident due to the Removal of Safety Fence from Gondola (곤돌라 안전난간 제거 등으로 인한 추락재해 감소방안)

  • Byun, Hyung Shik;Rhim, Jong kuk;Yang, Won Beak
    • Journal of the Korea Safety Management & Science
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    • v.21 no.2
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    • pp.9-14
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    • 2019
  • Gondola is widely used as a construction facility to perform external finishing work without using scaffolding at a construction site. However, since 2000, there have been 17 deaths from now so these risks associated with work can not be ignored. Therefore, it is expected that it will contribute greatly to prevent related disasters if introducing necessary measures to prevent repeated related disasters and installing additional safety devices. In order to eliminate the risk factor according to the operation of the gondola, it is necessary for the operator to use it to use it while the examination of each product is completed, and to use the over load Dangerous arbitrary measures such as arbitrary operation of the prevention device, removal of the safety fence for convenience of work, installation of the wire rope installed in the air, falling out of the wire rope and falling to the ground Do not perform such sealing measures so that any operation of the overload prevention device can not be done so as not to take such arbitrary measures, or wire the power supply wire to the safety fence so as not to delete the safety fence. Then, when the safety fence is removed, so that it does not become a gondola operation, or when replacing the wire rope in the air, to prevent the wire rope from coming off, Additional measures such as installing falling down prevention device may be necessary.

SPIT Prevention Framework using Expanded White List (확장 화이트리스트 기법을 이용한 SPIT 대응 프레임워크)

  • Bae, Kwang-Yong;Chae, Kang-Suk;Kim, Young-Beom
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.47 no.2
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    • pp.95-102
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    • 2010
  • This paper proposes a SPIT(Spam over IP Telephony) prevention framework which is using expanded white-list in real-time VoIP environment. The existing schemes are vulnerable to attack from spammers since they can continue to transfer SPIT upon changing their ID. And existing frameworks have experienced the time delay and overload as session initiates due to real-time operation. To solve these problems, the proposed scheme expands the scope of white lists by forming social networks using the white list, but it is to decide quickly whether pass a caller ID without searching the entire database. The proposed framework takes the three-stage architecture and the fast scoring system. The proposed framework minimize user's inconvenience and time delay for initiation of session, therefore, it is proper for real-time VoIP environment.

Frequency of Unnecessarily Biopsies among Patients with Suspicion of Prostate Cancer in Syrian Men

  • Bachour, Dala-Maria;Chahin, Emil;Al-Fahoum, Sahar
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.14
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    • pp.5967-5970
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    • 2015
  • Background: The prevalence of prostate cancer is considered high in many countries, and screening tests are very important in order to detect prostate cancer in its early stages; however false positivity with these screening tests means that a lot of patients undergo unnecessary biopsy, which is an invasive procedure, for the confirmatory test. The purpose of this study was to estimate the frequency of unnecessary biopsy cases in patients referred for prostate biopsy in one of the most important and overload cancer centers in Syria. Materials and Methods: Retrospective data for a period of four years between January 2009 and December 2012 were collected in Al-Bayrouni University Medical hospital in Damascus, Syria. The patients from whom data were collected were referred to our histopathological department because of elevated prostate specific antigen (PSA) serum or an abnormal digital rectal examination (DRE). All patients underwent prostatic TRUS-guided biopsies. Diagnosis of prostate cancer (PCa) or benign prostatic hyperplasia (BPH) was based on histopathological examination and prostate cancers cases were graded and scored according to the Gleason score system. Results: For the 406 patients referred to biopsy, the $mean{\pm}SD$ age was $58.4{\pm}23.3$ years. The $mean{\pm}SD$ PSA level was $49.2{\pm}21.5ng/ml$. Of the total we found 237 patients diagnosed with PCa (58. 4%), 166 patients with BPH (40.9%) and 3 cases were unable to be diagnosed (0.7%) because of biopsy collection errors. Conclusions: Our study shows that a high percentage of patients are undergoing unnecessary biopsy, which suggests that the performed screening tests had a high level of false positive and may need re-evaluation.

Effects of Task Stress on the Job Satisfaction of Fire Protection Management Workers (소방시설관리업 종사자의 직무스트레스가 직무만족에 미치는 영향)

  • Lim, Kyoung-Yeon;Kong, Ha-Sung
    • Fire Science and Engineering
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    • v.33 no.5
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    • pp.130-139
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    • 2019
  • This study identified the level of task stress experienced by fire protection system management workers and analyzed the effects of task stress on job satisfaction and proposed future response. First, task stress according to background cause showed differences in relation to age, position, monthly salary, total career, license, and task, but there was no difference in relation to academic background. Second, of the sub-parameters of stress, physical environment, task demand, organizational system, lack of reward, and workplace culture have negative effects on job satisfaction as stress increases, while interpersonal relation conflict and job insecurity do not have any effect. In the future, it will be necessary to investigate the empirical causes of work overload and to study organization-level stress relief measures.

Analysis of Thermal Characteristics for the Fire Risk Assessment According to Partial Disconnection on the VCTF and IV Electric Wire (VCTF와 IV전선의 반단선에 의한 화재위험성 평가를 위한 열적특성 해석)

  • Kim, Doo-Hyun;Kim, Sung-Chul;Lee, Jong-Ho;Park, Jong-Young;Park, Young-Ho;Lee, Hyung-Jun
    • Journal of the Korean Society of Safety
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    • v.23 no.4
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    • pp.47-52
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    • 2008
  • Many researches on fire risk for normal electric wiring have been pursued in advanced countries such as the USA and Japan, but comparative studies of the partial disconnection and normal state of electric wires have not been conducted. Detection system for the cause of partial disconnection is not developed and prevention countermeasure for electrical fire by the cause is not effective. Therefore, in this paper, partial disconnection characteristics on electric wires were derived and analyzed by experiment and electrical-thermal finite element method(Flux 3D) on the model wires which consist of VCTF(PVC insulated PVC sheathed Cap Tyre Flexible Cord, KS C 3304) and IV(lndoorwire PVC, KS C 3302). VCTF is used in wiring portable electric appliances and the IV is used indoors. Interrelationships between partial disconnection premonitory symptom and current were derived and analyzed by the characteristics based on experiments and thermal analysis for electric wire according to current under normal state and 200% overload state of rated current.

A Study on Prediction Reputation System for Prevention of SPIT (SPIT 차단을 위한 예측 평판도 기법에 대한 연구)

  • Bae, Kwang-Yong;Lee, Jae-Eun;Kim, Young-Beom
    • Journal of the Institute of Electronics and Information Engineers
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    • v.50 no.2
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    • pp.152-160
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    • 2013
  • This paper proposes a prediction reputation system for the anti-SPIT solution in real-time VoIP environment. The existing schemes need to get the user's feedback and/or have experienced the time delay and overload as session initiates due to real-time operation. To solve these problems, the proposed scheme predicts the reputation through the statistical analysis based on the period of session initiation of each caller and the call duration of each receiver. As per the second mentioned problem, this scheme performs the prediction before session initiation, therefore, it's proper for real-time VoIP environment.

A Study on Electric Safety Control Device for Prevention of Over Current and Short Circuit Faults (과전류 및 단락사고 방지용 전기안전 제어장치에 관한 연구)

  • Jo, Si-Hwan;Kwak, Dong-Kurl;Jung, Do-Young;Shim, Jae-Sun;Kim, Jung-Sook
    • Proceedings of the KIEE Conference
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    • 2008.07a
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    • pp.2100-2101
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    • 2008
  • This paper is studied on a protective control system for electrical fire and electrical faults due to over current or electric short circuit faults by using electrical thermal characteristics of PTC (Positive Temperature Coefficient) thermistor and current response characteristics of high sensitive reed switch. The PTC thermistor has characteristic of positive resistivity temperature coefficient according to the temperature variation, which is construction of a regular square and cube demarcation with BaTiO3_Ceramics of positive temperature coefficient. Also PTC thermistor shows the phenomenon which is rapidly increased in the resistivity if the temperature is increased over Curie temperature point, and reed switch, which is used for electrical fault current sensing devices, have a excellent characteristic of response velocity in degree of ${\mu}s{\sim}ms$ that sensing magnetic flux in proportion to dimension of line current. This paper is proposed on a protective control system use PTC thermistor and reed switch for sensor which is protected from electrical fire due to overload faults or electric short circuit faults. Some experimental results of the proposed electric safety control device are confirmed to the validity of the analytical results.

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EGCG Blocked Phenylephrin-Induced Hypertrophy in H9C2 Cardiomyocytes, by Activating AMPK-Dependent Pathway

  • Cai, Yi;Zhao, Li;Qin, Yuan;Wu, Xiao-Qian
    • The Korean Journal of Physiology and Pharmacology
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    • v.19 no.3
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    • pp.203-210
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    • 2015
  • AMP-activated protein kinase (AMPK) is a key regulator of energy metabolism. Previous studies have shown that activation of AMPK results in suppression of cardiac myocyte hypertrophy via inhibition of the p70S6 kinase (p70S6K) and eukaryotic elongation factor-2 (eEF2) signaling pathways. Epigallocatechin-3-gallate (EGCG), the major polyphenol found in green tea, possesses multiple protective effects on the cardiovascular system including cardiac hypertrophy. However, the molecular mechanisms has not been well investigated. In this study, we found that EGCG could significantly reduce natriuretic peptides type A (Nppa), brain natriuretic polypeptide (BNP) mRNA expression and decrease cell surface area in H9C2 cardiomyocytes stimulated with phenylephrine (PE). Moreover, we showed that AMPK is activated in H9C2 cardiomyocytes by EGCG, and AMPK-dependent pathway participates in the inhibitory effects of EGCG on cardiac hypertrophy. Taken together, our findings provide the first evidence that the effect of EGCG against cardiac hypertrophy may be attributed to its activation on AMPK-dependent signaling pathway, suggesting the therapeutic potential of EGCG on the prevention of cardiac remodeling in patients with pressure overload hypertrophy.