• Title/Summary/Keyword: reliability and safety

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A Study on the Crime Prevention Design and Consumer Perception (CPTED) of Multi-Family Housing in China (중국 공동주택의 범죄 예방을 위한 디자인과 소비자의 인식에 관한 연구)

  • Kong, De Xin;Lee, Dong Hun;Park, Hae Rim
    • Journal of Service Research and Studies
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    • v.14 no.1
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    • pp.63-76
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    • 2024
  • Multi-family housing plays a crucial role as a living and experiencing space, and its environment has a direct impact on the well-being and stability of its residents. Therefore, Crime Prevention Design (CPTED) for multi-family housing is of utmost importance. However, crime-related data in China is not disclosed to the public because of its specificity, making it difficult for researchers to conduct further in-depth studies based on accurate crime data. As a result, the establishment and application of CPTED theory in terms of crime prevention is limited and delayed. This study aims to explore three aspects of CPTED in multi-family housing as perceived by home-buying consumers. It investigated consumer perception of the CPTED, the importance of each element and ways to increase awareness of CPTED in multifamily housing in order to effectively improve multifamily crime prevention design principles and further enhance public safety. This study examined the current state and future trends of CPTED in China by analyzing relevant research reports and literature, aiming to gain insights into the crime prevention awareness of Chinese homeowners. In addition, a survey was conducted on Chinese consumers to unravel the importance of CPTED and increase awareness of its various elements in multifamily-family. This study used a Likert scale and SPSS reliability analysis to determine the cognitive status of multi-family CPTED, the importance of each element, and proposed an improvement plan based on the analysis results. As this study was limited by the difficulty of implementation and the lack of validation of its practical effectiveness, it is recommended that future research needs to validate the effectiveness of crime prevention designs and produce more practical results. Furthermore, it is crucial to utilize this study to inform the implementation of security solutions that are tailored to the unique characteristics of each district. Additionally, it is important to offer guidance on how to enhance community safety by increasing residents' awareness of security through education and information dissemination. The author hopes that the representative multi-family CPTED awareness, the importance of each element, and plans for improvement shall be summarized from this study, and provide foundational data for the future development of CPTED based on the Chinese region.

A Study on Load-carrying Capacity Design Criteria of Jack-up Rigs under Environmental Loading Conditions (환경하중을 고려한 Jack-up rig의 내하력 설계 기준에 대한 연구)

  • Park, Joo Shin;Ha, Yeon Chul;Seo, Jung Kwan
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.26 no.1
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    • pp.103-113
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    • 2020
  • Jack-up drilling rigs are widely used in the offshore oil and gas exploration industry. Although originally designed for use in shallow waters, trends in the energy industry have led to a growing demand for their use in deep sea and harsh environmental conditions. To extend the operating range of jack-up units, their design must be based on reliable analysis while eliminating excessive conservatism. In current industrial practice, jack-up drilling rigs are designed using the working(or allowable) stress design (WSD) method. Recently, classifications have been developed for specific regulations based on the load and resistance factor design (LRFD) method, which emphasises the reliability of the methods. This statistical method utilises the concept of limit state design and uses factored loads and resistance factors to account for uncertainly in the loads and computed strength of the leg components in a jack-up drilling rig. The key differences between the LRFD method and the WSD method must be identified to enable appropriate use of the LRFD method for designing jack-up rigs. Therefore, the aim of this study is to compare and quantitatively investigate the differences between actual jack-up lattice leg structures, which are designed by the WSD and LRFD methods, and subject to different environmental load-to-dead-load ratios, thereby delineating the load-to-capacity ratios of rigs designed using theses methods under these different enviromental conditions. The comparative results are significantly advantageous in the leg design of jack-up rigs, and determine that the jack-up rigs designed using the WSD and LRFD methods with UC values differ by approximately 31 % with respect to the API-RP code basis. It can be observed that the LRFD design method is more advantageous to structure optimization compared to the WSD method.

Experimental Study on Ignition and Explosion Hazard by Measuring the Amount of Non-volatile (NVR) and Explosion Limit of Biodiesel Mixture (바이오디젤 혼합물의 가열잔분측정과 폭발한계 측정을 통한 발화 및 폭발위험성에 대한 실험적인 연구)

  • Kim, Ju Suk;Koh, Jae-Sun
    • Journal of the Society of Disaster Information
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    • v.18 no.1
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    • pp.182-193
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    • 2022
  • Purpose: By measuring and evaluating the risk of biodiesel through non-volatile residue (NVR) and flash point and explosion limit measurement at a specific temperature according to ASTM test standards, the risk of chemical fire causative substances is identified and a universal evaluation method By derivation and securing the risk-related data of the material, it can be used for the identification and analysis of the cause of the fire, and it can be applied to the risk assessment of other chemical substances Method: In order to measure the risk of biodiesel, it was measured using the non-volatile residue(NVR) measurement method, which measures how much flammable liquid is generated at a specific temperature. Heating was tested by applying KS M 5000: 2009 Test Method 4111. In addition, the flash point was measured using the method specified in ASTM E659-782005, and the energy supply method was measured using the constant temperature method. In addition, the explosion limit measurement was conducted in accordance with ASTM E 681-04 「Standard test method for concentration limits of flammability of chemicals(Vapors and gases)」 test standard. Result: As a result of checking the amount of combustible liquid by the non-volatile residue (NVR)measurement method, the non-volatile residue(NVR) of general diesel when left at 105±2℃ for 3 hours was about 30% (70% of volatile matter) and about 4% of biodiesel. In addition, similar results were obtained for the non-volatile residue(NVR)heating temperature of 150±2℃, 3 hours and 200±2℃ for 1 hour, and white smoke was generated at 200℃ or higher. In addition, similar values were obtained as a result of experimentally checking the explosion (combustion) limits of general diesel, general diesel containing 20% biodiesel, and 100% biodiesel. Therefore, it was confirmed that the flammability risk did not significantly affect the explosion risk. Conclusion: The results of this study suggested the risk judgment criteria for mixtures through experimental research on flammable mixtures for the purpose of securing the effectiveness, reliability, and reproducibility of the details of the criteria for determining dangerous substances in the existing Dangerous Materials Safety Management Act. It will be possible to provide reference data for the judgment criteria for flammable liquids that are regulated in the field. In addition, if the know-how for each test method is accumulated through this study, it is expected that it will be used as basic data in the research on risk assessment of dangerous substances and as a basis for research on the determination of dangerous substances.

A Study on the Effects of Droplets Characteristics of Water Mist on the Spray Density on the Floor (미분무 액적특성이 살수밀도에 미치는 영향 연구)

  • Kim, Jong-Hoon;Park, Won-Hee;Kim, Woon-Hyung;Myoung, Sang-Yup
    • Journal of the Society of Disaster Information
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    • v.17 no.1
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    • pp.120-127
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    • 2021
  • Purpose: In this study, the effect of changes in the variables related to water droplets on the spray density on the floor in the analysis of the water mist fire protection system using FDS was analyzed. Method: When the spray of the water mist nozzle was analyzed in FDS, Particles Per Seconds, Particle Velocity, Size Distribution, and Spray Pattern Shape that can be set in relation to droplets were input to review the analyzed results. Result: In the analysis results, when the number of particles per second was set above a certain value, the spray density of the floor was similar. In the case of Particle Velocity, as the velocity decreases, the spray density of the central portion increases but decreases at a distance of 0.15m or more. From the analysis of the change in the size distribution function, it was found that an increase in the 𝛾 value increases the spray density of the central part, but the value at a remote location decreases. Compared to the result of applying the Gaussian distribution, the median value decreases dramatically when the uniform distribution is applied, but the value at the adjacent position increases. Conclusion: Variables related to the droplet properties of the FDS affect the spray density of the floor. Therefore, in order to increase the reliability of results before performing analyses such as fire suppression or cooling, a sufficient review of input variables is required.

A Study on the Antigastritic Effects of Rheum Species Extracts and Their Active Components (대황 추출물의 항위염 작용과 유효성분에 관한 연구)

  • Hwang, In Young;Jeong, Choon Sik
    • Journal of Food Hygiene and Safety
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    • v.28 no.4
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    • pp.330-336
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    • 2013
  • Rheum tanguticum has long been used in oriental medicine as antipyretics, analgesics, anti-inflammation, aperient, hypertension medicine and medicine for skin disease. This study has investigated the effectiveness of defense for gastritis making use of Rheum tanguticum and its similar plants, Rumex cripus, Rheum officinale, Rhem palmatum and Rheum undulatum. Chysophanol, chrysophanol-8-O-glc, Desoxyrhaponticin desoxyrhaponti-genin, emodin, isorhaponticin, 2-methoxy-4-hydroxyanthraquinone-5-O-glc, physcion, pirace-tannol-3'-O-glc, resveratrol, rhaponticin and rhapontigenin are used as the components of Rheum tanguticum. In HCl ethanol-induced gastritis in rat, the most effective extract was 70 percent ethanol which is of Rheum tanguticum, showing the inhibition of 91.8 percent to the gastric lesions. 70% ethanol extract of Rhem palmatum and Rumex cripus shown inhibition of 75.6 percent and 73.2 percent, respectively. This effectiveness is considered as acid-neutralizing capacity, anti-H.pylori and anti-oxidant activity. 70% ethanol extract of Rheum tanguticum and its component, piracetannol-3'-O-glc exhibited higher free radical scavenging activity than others. These results suggest that Rheum species extracts and their active components could be utilized for the treatment of gastritis. Furthermore, these results are expected to contribute the standardization with objectivity and reliability for Rheum species, medicinal herbs. In addition, it can contribute to the prevention of indiscriminate distribution of imitation, and the rising rate of dependence on imports of medicinal herbs, and mixing prevention of low-quality goods.

Real-Time AT-PCR for Quantitative Detection of Bovine Parainfluenza Virus Type 3 during the Manufacture of Biologics (생물의약품 제조공정에서 Bovine Parainfluenza Virus Type 3 정량 검출을 위한 Real-Time RT-PCR)

  • Lee, Dong-Hyuck;Kim, Chan-Kyong;Kim, Tae-Eun;Kim, In-Seop
    • KSBB Journal
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    • v.23 no.4
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    • pp.303-310
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    • 2008
  • Bovine blood, cell, tissue, and organ are used as raw materials for manufacturing biologics such as biopharmaceuticals, tissue-engineered products, and cell therapy. Manufacturing processes for the biologics have the risk of viral contamination. Therefore viral validation is essential in ensuring the safety of the products. Bovine parainfluenza virus type 3 (BPIV3) is one of the common bovine pathogens and has widely been known as a contaminant of biologics. In order to establish the validation system for the BPIV3 safety of biologics, a real-time RT-PCR method was developed for quantitative detection of BPIV3 contamination in raw materials, manufacturing processes, and final products. Specific primers for amplification of BPIV3 RNA was selected, and BPIV3 RNA was quantified by use of SYBR Green I. The sensitivity of the assay was calculated to be 2.8 $TCID_{50}/mL$. The real-time RT-PCR method was validated to be reproducible and very specific to BPIV3. The established real-time RT-PCR assay was successfully applied to the validation of Chinese hamster ovary (CHO) cell artificially infected with BPIV3. BPIV3 RNA could be quantified in CHO cell as well as culture supernatant. Also the real-time RT-PCR assay could detect 7.8 $TCID_{50}/mL$ of BPIV3 artificially contaminated in bovine collagen. The overall results indicated that this rapid, specific, sensitive, and robust assay can be reliably used for quantitative detection of BPIV3 contamination during the manufacture of biologics.

The Situation and the Tasks of UK Rail Privatization, Focusing on after the Hatfield Accident (영국 철도 민영화의 현황 및 과제 (Hatfield사고 이후의 변화를 중심으로))

  • Lee, Yong-Sang
    • Journal of Korean Society of Transportation
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    • v.24 no.2 s.88
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    • pp.91-100
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    • 2006
  • This paper examines the situation and tasks of UK rail privatization, especially focusing on after the Hatfield rail accident. Earlier research which focused on the UK's Privatization had little knowledge of the explanations for recent changes. Moreover they had difficulty making a direct comparison between national rail and the privatized rail. Therefore we aye left without a good explanation which has a comprehensive perspective. I attempt to show the change in the rail privatization Process and its outcome, focusing on after the Hatfield rail accident. This Paper argues that the UK's vail privatization process has a regulatory framework which is too complicated with overlapping responsibilities that brought about inefficiency, increasing costs and a superficial safety regime. Especially the planning of rail and infrastructure maintenance did not come to play an appropriate role. However after 2000, the government took charge of setting the strategy for railways, and the Office of Rail Regulation covered safety performance and cost. explain that these changes present a good opportunity to solve the problem of passing the buck for poor performance. Through the analysis, I find that the passenger rail network is well-suited to deliver long distance business and commuters and that the subsidy from the government is decreasing. However, performance, for example punctuality and reliability. should be improved. Especially the Hatfield rail accident caused a reduction in the satisfaction of passengers. In future. the problems of rising costs and monopoly franchise system should be addressed.

Improvements in the Environmental Impact Assessment on Seawater and Sediment Qualities for Coastal Dredging Projects (연안준설 사업에 따른 해양 수질 및 퇴적물 영향평가 개선 방안)

  • Kim, Yeong-Tae;Kim, Gui-Young;Jeon, Kyeong-Am;Lee, Dae-In;Yu, Jun;Kim, Hee-Jung;Kim, In-Chul;Eom, Ki-Hyuk
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.19 no.2
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    • pp.119-128
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    • 2013
  • Since the early 2000s, demand for coastal dredging projects have been significantly increased, and the dredged sediments have showed the continuing marked increases through the multiple projects with other coastal development and constructions. As significant or potential degradation of marine environment has been mounting, we checked the current situation of marine environmental impact assessment through marine water and sediment qualities in relation with dredging projects of the sea area utilization consultation statements submitted in 2011. While analysis percentages of the general items were usually higher, harmful components such as metals revealed wide variation of analysis percentages. In the event of analysis of metals, the pre-treatment process (full digestion) and analysis method were not properly implemented in accordance with the guidelines for preparation of consultation statements. Although not specified in the guidelines, verification procedures (tests of recovery efficiency and detection limit) to secure the reliability were almost ignored. As a result, most of developers did conduct poor marine environmental impact assessment on coastal dredging and related projects. We suggested that the responsible government authority should establish new detailed guidelines on the sea area utilization consultation for more strict evaluation and diagnosis of marine environment and distinctly request the developer to obey the guidelines by complementing the system of the sea area utilization consultation.

Detection and Measurement of Nuclear Medicine Workers' Internal Radioactive Contamination (핵의학과 종사자의 방사성동위원소 체내오염 측정)

  • Jeong, Gyu-Hwan;Kim, Yong-Jae;Jang, Jeong-Chan;Lee, Jai-Ki
    • The Korean Journal of Nuclear Medicine Technology
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    • v.13 no.3
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    • pp.123-131
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    • 2009
  • Purpose: We tested a sample of nuclear medicine workers at Korean healthcare institutions for internal contamination with radioactive isotopes, measuring concentrations and evaluating doses of individual exposure. Materials and Methods: The detection and measurement was performed on urine samples collected from 25 nuclear medicine workers at three large hospitals located in Seoul. Urine samples were collected once a week, 100~200 mL samples were gathered up to 6~10 times weekly. A high-purity germanium detector was used to measure gamma radiations in urine samples for the presence of radioactive isotopes. Based on the detection results, we estimated the amounts of intake and committed effective doses using IMBA software. In cases where committed effective doses could not be adequately evaluated with IMBA software, we estimated individual committed effective doses for radionuclides with a very short half life such as $^{99m}Tc$ and $^{123}I$, using the methods recommended by International Atomic Energy Agency. Results: Radionuclides detected through the analysis of urine samples included $^{99m}Tc$, $^{123}I$, $^{131}I$ and $^{201}Tl$, as well as $^{18}F$, a nuclide used in Positron Emission Tomography examinations. The committed effective doses, calculated based on the radionuclide concentrations in urine samples, ranged from 0 to 5 mSv, but were, in the majority of cases, less than 1 mSv. The committed effective dose exceeded 1 mSv in three of the samples, and all three were workers directly handling radioactive sources. No nurses were found to have a committed effective dose in excess of 1 mSv. Conclusions: To improve the accuracy of results, it may be necessary to conduct a long-term study, performed over a time span wide enough to allow the clear determination of the influence of seasonal factors. A larger sample should also help increase the reliability of results. However, as most Korean nuclear medicine workers are currently not necessary to monitored routinely for internal contamination with radionuclides. Notwithstanding, a continuous effort is recommended to reduce any unnecessary exposure to radioactive substances, even if in inconsequential amounts, by regularly surveying workplace environments and frequently monitoring atmospheric concentrations of radionuclides.

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Real-Time PCR for Quantitative Detection of Bovine Herpesvirus Type 1 (Bovine Herpesvirus Type 1 정량 검출을 위한 Real-Time PCR)

  • Lee, Dong-Hyuck;Jeong, Hyo-Sun;Lee, Jung-Hee;Kim, Tae-Eun;Lee, Jung-Suk;Kim, In-Seop
    • Korean Journal of Microbiology
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    • v.44 no.1
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    • pp.14-21
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    • 2008
  • Bovine blood, cell, tissue, and organ are used as raw materials for manufacturing biopharmaceuticals, tissue engineered products, and cell therapy. Manufacturing processes for the biologicals using bovine materials have the risk of viral contamination. Therefore viral validation is, essential in ensuring the safety of the products. Bovine herpesvirus type 1 (BHV-1) is the most common bovine pathogen found in bovine blood, cell, tissue, and organ. In order to establish the validation system for the BHV-1 safety of the products, a real-time PCR method was developed for quantitative detection of BHV-1 in raw materials, manufacturing processes, and final products as well as BHV-1 clearance validation. Specific primers for amplification of BHV-1 DNA was selected, and BHV-1 DNA was quantified by use of SYBR Green I. The sensitivity of the assay was calculated to be $2\;TCID_{50}/ml$. The real-time PCR method was validated to be reproducible and very specific to BHV-1. The established real-time PCR assay was successfully applied to the validation of Chinese hamster ovary (CHO) cell artificially infected with BHV-1. BHV-1 DNA could be quantified in CHO cell as well as culture supernatant. Also the real-time PCR assay could detect $10\;TCID_{50}/ml$ of BHV-1 artificially contaminated in bovine collagen. The overall results indicated that this rapid, specific, sensitive, and robust assay can be reliably used for quantitative detection of BHV-1 contamination during the manufacture of biologics.