• Title/Summary/Keyword: Safety-critical System

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Progressive collapse of steel-framed gravity buildings under parametric fires

  • Jiang, Jian;Cai, Wenyu;Li, Guo-Qiang;Chen, Wei;Ye, Jihong
    • Steel and Composite Structures
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    • v.36 no.4
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    • pp.383-398
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    • 2020
  • This paper investigates the progressive collapse behavior of 3D steel-framed gravity buildings under fires with a cooling phase. The effect of fire protections and bracing systems on whether, how, and when a gravity building collapses is studied. It is found that whether a building collapses or not depends on the duration of the heating phase, and it may withstand a "short-hot" fire, but collapses under a mild fire or a "long-cool" fire. The collapse time can be conservatively determined by the time when the temperature of steel columns reaches a critical temperature of 550 ℃. It is also found that the application of a higher level of fire protection may prevent the collapse of a building, but may also lead to its collapse in the cooling phase due to the delayed temperature increment in the heated members. The tensile membrane action in a heated slab can be resisted by a tensile ring around its perimeter or by tensile yielding lines extended to the edge of the frame. It is recommended for practical design that hat bracing systems should be arranged on the whole top floor, and a combination of perimeter and internal vertical bracing systems be used to mitigate the fire-induced collapse of gravity buildings. It is also suggested that beam-to-column connections should be designed to resist high tensile forces (up to yielding force) during the cooling phase of a fire.

Efficacy and safety of radioiodine therapy for 10 hyperthyroid cats: a retrospective case series study in South Korea

  • Yeon Chae;Jae-Cheong Lim;Taesik Yun;Yoonhoi Koo;Dohee Lee;Mhan-Pyo Yang;Hakhyun Kim;Byeong-Teck Kang
    • Korean Journal of Veterinary Research
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    • v.64 no.2
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    • pp.10.1-10.9
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    • 2024
  • Hyperthyroidism, characterized by elevated thyroid hormone levels and thyroid gland hyperplasia or adenoma, is a prevalent endocrinopathy in older cats. Treatment options include antithyroid drugs, surgical thyroidectomy, and radioiodine therapy (RAIT), which is non-invasive treatment option that can achieve complete remission. However, efficacy and safety of RAIT in hyperthyroid cats have not been investigated in South Korea. This study includes 10 hyperthyroid cats with RAIT. Initial assessments comprised history, physical examination, blood analysis, and serum total T4 (tT4) concentration. Thyroid scintigraphy revealed hyperactivity and enlargement of thyroid gland at 24 hours before the RAIT. Radioiodine (RAI) was injected subcutaneously with 2 to 6 mCi, determined by the fixed dose or the scoring system based on severity of clinical signs, tT4 concentration, and thyroid size individually. After RAIT, the concentration of serum tT4 and liver enzymes were significantly decreased at discharge. However, no significant differences were noted in blood urea nitrogen, creatinine, symmetric dimethylarginine, hematocrits, and white blood cell counts pre- and post-treatment. Although 4 cats received RAI twice, clinical signs disappeared and tT4 levels decreased following the RAIT. All 10 cats achieved complete remission after 6 months without critical adverse effect. The safety and the effectiveness of RAIT was confirmed based on protocols reported other countries. Therefore, RAIT could be considered the treatment option and prevent adverse effects from medication or surgery. This preliminary study presents the first evaluation of RAIT for hyperthyroid cats using locally produced RAI in South Korea and provide valuable insight for clinicians and further studies.

An Improvement of the State Assessment for Concrete Floor Slab by Damage Type Breakdown (손상유형 분할에 의한 콘크리트 바닥판의 상태평가 개선)

  • Hwang, Jin Ha;An, Seoung Su
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.12 no.2
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    • pp.139-148
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    • 2008
  • The direct inspection of the outward aspects by field engineers is the important and critical part for structural safety assessment according to the related reports. This study presents an improved method of the state assessment for concrete floor slab by separating and evaluating the individual damage types. First, the various types of damage symptoms are separated, which have been included and dealt in a group. Secondly, they are weighted and scored independently based on the present guide and references. Overall procedures other than the above are retained as same as possible to avoid the confusion. The proposed method is applied and tested to a performed assessment project for a bridge for validation. The result shows that it is reasonable and applicable in respect that it is able to make up for the controversial points of the present guide revealed in practices. Careful check of excessively deteriorated parts in addition to the reasonable assessment of system by this method grants the structural repair and reinforcement propriety and economy, and assures of more safety. Twofold appraisal of this approach expands the applicable areas of value engineering to the structural maintenance.

Case Study of Applying DO-278A for Advanced Surface Movement Guidance & Control System (DO-278A 표준을 적용한 A-SMGCS 개발 사례 연구)

  • Jo, Sanghoon;Lee, Hongseok;Kim, Jha-young;Yi, Jin-geun
    • Journal of Advanced Navigation Technology
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    • v.20 no.2
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    • pp.127-133
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    • 2016
  • This paper proposes a case study of applying to DO-278A, which is a software development standard of ground aviation equipment in communication, navigation, surveillance/air traffic management (CNS/ATM) domain, in order to develop software of Advanced surface movement, guidance and control system (A-SMGCS). It explains considerations to application of DO-278A standard, discusses how to tailor processes or requirements specified in DO-278A in detail, and explain tailored results. And it also summary problems or issues occurred during application of DO-278A, which can be appeared when DO-278A is applied to for the first time by any development part. These are required considerations in order to reduce trial and error. To the conclusion, it explains lessons learned from application of DO-278A and suggest how to solve these problems or issues.

A Study on the Development of an RFID System for Recreational Boating Safety (RFID 기술을 활용한 해양인명구조 시스템 개발에 관한 연구)

  • Yang, Dong-Shin;Sung, Chul;Choi, Tae-Sung
    • Proceedings of KOSOMES biannual meeting
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    • 2006.11a
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    • pp.119-123
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    • 2006
  • Finding out the exact location of survivors in short period of time is critical to conduct rescue activity successfully in oceans. Current technology with natural circumstances limits the activity that our efforts come along. R&D Center housed at Korea Coast Guard (KCG) has developed the system named "RFID for Life jacket" which enables us to access the location of persons under distressed situation. The RFID has been widely known as state-of-art technology to monitor the location even in inland or in ocean. Composed of tag, antenna. reader and middleware, RFID is attached to attached to a life jacket that people usually wears in recreational activity. By conducting experiments in pilot-scale several times, successful results showing 96.7% of transmission within 3.5km in diameter were produced. This study explains the routes of experiments to reach the goal and expected results coming from this accomplishments.

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Development of Integrated System of Time-Driven Activity-Based Costing(TDABC) Using Balanced Scorecard(BSC) and Economic Value Added(EVA) (BSC와 EVA를 이용한 TDABC 통합시스템의 개발)

  • Choi, Sungwoon
    • Journal of the Korea Safety Management & Science
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    • v.16 no.3
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    • pp.451-469
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    • 2014
  • The purpose of this study is to implement and develop the integrated Economic Value Added (EVA) and Time-Driven Activity-Based Costing (TDABC) model to seek both improvement of Net Operating Profit Less Adjusted Tax (NOPLAT) and reduction of Capital Charge (CC). Net Operating Profit Less Adjusted Tax (NOPLAT) can be maximized by reducing the indirect cost of an unused resource capacity increased by Cost Capacity Ratio (CCR) of TDABC. On the other hand, Capital Charge (CC) can be minimized by improving the efficiency of Invested Capital (IC) considered by Weighted Average Cost of Capital (WACC) of EVA. In addition, the integrated system of TDABC using Balance Scorecard (BSC) and EVA is developed by linking between the lagging indicators and the three leading indicators. The three leading indicators include customer, internal process and growth and learning perspectives whereas the lagging indicator includes NOPLAT and CC in terms of financial perspective. When the Critical Success Factor (CSF) of BSC is cascading as a cause and an effect relationship, time driver of TDABC and capital driver of EVA can be used efficiently as Key Performance Indicator (KPI) of BSC. For a better understanding of the proposed EVA/TDABC model and BSC/EVA/TDABC model, numerical examples are derived from this paper. From the proposed model, the time driver of TDABC and the capital driver of EVA are known to lessen indirect cost from comprehensive income statement when increasing the efficiency of operating IC from the statement of financial position with unified KPI cascading of aligned BSC CSFs.

Modeling and coupling characteristics for an airframe-propulsion-integrated hypersonic vehicle

  • Lv, Chengkun;Chang, Juntao;Dong, Yilei;Ma, Jicheng;Xu, Cheng
    • Advances in aircraft and spacecraft science
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    • v.7 no.6
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    • pp.553-570
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    • 2020
  • To address the problems caused by the strong coupling of an airbreathing hypersonic vehicle's airframe and propulsion to the integrated control system design, an integrated airframe-propulsion model is established, and the coupling characteristics between the aircraft and engine are analyzed. First, the airframe-propulsion integration model is established based on the typical nonlinear longitudinal dynamical model of an air-breathing hypersonic vehicle and the one-dimensional dual-mode scramjet model. Thrust, moment, angle of attack, altitude, and velocity are used as transfer variables between the aircraft model and the engine model. The one-dimensional scramjet model can accurately reflect the working state of the engine and provide data to support the coupling analysis. Second, owing to the static instability of the aircraft model, the linear quadratic regulator (LQR) controller of the aircraft is designed to ensure attitude stability and height tracking. Finally, the coupling relationship between the aircraft and the engine is revealed through simulation examples. The interaction between vehicle attitude and engine working condition is analyzed, and the influence of vehicle attitude on engine safety is considered. When the engine is in a critical working state, the attitude change of the aircraft will not affect the engine safety without considering coupling, whereas when coupling is considered, the attitude change of the aircraft may cause the engine unstart, which demonstrates the significance of considering coupling characteristics.

Post-buckling Behaviour of Aluminium Alloys Rectangular Plate Considering the Initial Deflection Effect (초기 처짐 영향을 고려한 알루미늄 합금 사각형 판의 좌굴 후 거동)

  • Oh, Young-Cheol;Kang, Byoung-Mo;Ko, Jae-Yong
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.20 no.6
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    • pp.738-745
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    • 2014
  • In this paper, It is performing to the elastic and elasto-plastic large deformation series analysis using a numerical method for the initial deflection effect of the aluminum alloy rectangular plate in the elasto-plastic loading area patch loading size. It is assumed a boundary condition to be a simply supported condition and consider the initial deflection amplitude, aspect ratio. It examined the critical elastic buckling load and post-buckling behaviour of aluminium alloy A6082-T6 rectangular plate. It used a commercial program for the elastic and elasto-plastic deformation series analysis. If the initial deflection amplitude is smaller, the in-plane rigidity with increasing to load is reduced from the start and occurs significantly more increasing the amplitude. More higher the aspect ratio, the initial yield strength is gradually decreased, and the plate thickness thicker and occurs larger than the thin walled plate a reduction ratio of the initial yield strength of the patch loading size as 0.5.

Shell Valve Movement of Pacific Oysters, Crassostrea gigas, in Response to Low Salinity Water (저염수에서 이매패류 참굴(Crassostrea gigas)의 패각운동)

  • Moon, Suyeon;Oh, Seok Jin
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.23 no.6
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    • pp.684-689
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    • 2017
  • We examined the possibility of developing an early monitoring system using the shell valve movement activity of Pacific oyster (Crassostrea gigas) for early detection of low salinity water in coastal areas. At salinity levels of 30 psu and 20 psu, SVMs were detected $7.32{\pm}3.21times/hr$ and $7.11{\pm}3.90times/hr$, respectively, The patterns and times of SVMs were not significantly different between the two experiment phases. However, at 10 psu and 5 psu, shell valves were observed to be permanently closed in all experiments. Under combined condition (Group 1: temperature $15^{\circ}C$ ${\times}$ salinity 15 psu), SVMs were observed from 20 psu to 30 psu over a 2 - 3 hr period, and then remained closed. In Group 2 (temperature $30^{\circ}C$ ${\times}$ salinity 15 psu), SVMs were observed, which indicated that the physiological condition of the oysters reached a critical point. Thus, it may be possible to utilize SVMs as an early warning signal for low salinity water.

A Study on the Management and Dispensing Standards of Herbal Medicine in Herbal Dispensaries (탕전실의 조제 관리 및 운영 기준에 대한 연구)

  • Kang, Sung Chul;Kim, So Yeon;Yun, Yu Kyung;Kim, Ji-Hoon;Kim, Yun-Kyung
    • Herbal Formula Science
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    • v.27 no.1
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    • pp.31-44
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    • 2019
  • Objective : Herbal dispensaries, where medications are prepared for patients, require specific preparation and operations management for safe herbal medicines. This study aims to propose improvements in the herbal medicine preparation and operation of the herbal dispensaries as series study of the "A Survey on the Management Status of Extramural Herbal Dispensaries" Methods : We first checked current management regulations. In addition, we compared and analyzed related laws which are "State management norm of Traditional Chinese Medicine dispensaries", "Enforcement Rule of Medicinal Product Safety" and " Hazard Analysis and Critical Control Point(HACCP)", to introduce the assessment items of herbal dispenses evaluation and certification system. Results : In this study, we found that the current regulations, "Guideline on Installation and Utilization of Extremal Herbal Pharmaceutical Facility and Shared-use of Herbal Dispensary", are insufficient to ensure the quality and safety of herbal medicines. We suggested articles for the proper management of herbal dispensaries and these were introduced to the Herbal dispensary evaluation and certification system. Conclusion : We recommend evaluation articles in Herbal dispensary evaluation and certification systems need to be popular among herbal dispensaries, then Korean herbal medicine could restore credibility from the people.