• Title/Summary/Keyword: safety analysis

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Radioanalytical and Spectroscopic Characterizations of Hydroxo- and Oxalato-Am(III) Complexes (방사분석과 분광학을 이용한 Am(III) 가수분해와 옥살레이트 착물 화학종 연구)

  • Kim, Hee-Kyung;Cho, Hye-Ryun;Jung, Euo Chang;Cha, Wansik
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.16 no.4
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    • pp.397-410
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    • 2018
  • When considering the long-term safety assessment of spent-nuclear fuel management, americium is one of the most radio-toxic actinides. Although spectroscopic methods are widely used for the study of actinide chemistry, application of those methods to americium chemistry has been limited. Herein, we purified $^{241}Am$ to obtain a highly pure stock solution required for spectroscopic studies. Quantitative and qualitative analyses of purified $^{241}Am$ were carried out using liquid scintillation counting, and gamma and alpha radiation spectrometry. Highly sensitive absorption spectrometry coupled with a liquid waveguide capillary cell and time-resolved laser fluorescence spectroscopy were employed for the study of Am(III) hydrolysis and oxalate (Ox) complexation. $Am^{3+}$ ions under acidic conditions exhibit maximum absorbance at 503 nm, with a molar absorption coefficient of $424{\pm}8cm^{-1}{\cdot}M^{-1}$. $Am(OH)_3(s)$ colloidal particles formed under near neutral pH conditions were identified by monitoring the absorbance at around 506-507 nm. The formation of ${Am(Ox)_3}^{3-}$ was detected by red-shifts of the absorption and luminescence spectra of 4 and 5 nm, respectively. In addition, considerable enhancements of the luminescence intensities were observed. The luminescence lifetime of ${Am(Ox)_3}^{3-}$ increased from 23 to 56 ns, which indicates that approximately six water molecules are replaced by carboxylate ligands in the inner-sphere of the Am(III). These results suggest that ${Am(Ox)_3}^{3-}$ is formed through the bidentate coordination of the oxalate ligands.

A study on the field application of high strength steel pipe reinforcement grouting (고강도 강관 보강 그라우팅의 현장 적용성에 관한 연구)

  • Shin, Hyunkang;Jung, Hyuksang;Ryu, Yongsun;Kim, Donghoon
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.21 no.4
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    • pp.455-478
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    • 2019
  • In this paper, we conducted experimental investigation on the field applicability through the verification of reinforcement effect of the steel pipe reinforcement grouting using high strength steel pipe. SGT275 (formerly known as STK400) steel pipe is generally applied to the traditional steel pipe reinforcement grouting method. However, the analysis of tunnel collapse cases applying the steel pipe reinforcement grouting shows that there are cases where the excessive bending and breakage of steel pipe occur. One of the reasons causing these collapses is the lack of steel pipe stiffness responding to the loosening load of tunnels caused by excavation. The strength of steel pipe has increased due to the recent development of high strength steel pipe (SGT550). However, since research on the reinforcement method considering strength increase is insufficient, there is a need for research on this. Therefore, in this study, we conducted experiments on the tensile and bending strength based on various conditions between high strength steel pipe, and carried out basic research on effective field application depending on the strength difference of steel pipe through the conventional design method. In particular, we verified the reinforcement effect of high strength steel pipe through the measurement results of deformed shape and stress of steel pipe arising from excavation after constructing high strength steel pipe and general steel pipe at actual sites. The research results show that high strength steel pipe has excellent bending strength and the reinforcement effect of reinforced grouting. Further, it is expected that high strength steel pipe will have an arching effect thanks to strength increase.

Analysis of Automotive HMI Characteristics through On-road Driving Research (실차 주행 연구를 통한 차량별 HMI 특성 분석)

  • Oh, Kwangmyung
    • Journal of the HCI Society of Korea
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    • v.14 no.2
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    • pp.49-60
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    • 2019
  • With the appearance of self-driving cars and electric cars, the automobile industry is rapidly changing. In the midst of these changes, HMI studies are becoming more important as to how the driver obtains safety and convenience with controlling the vehicle. This study sought to understand how automobile manufacturers understand the driving situation, and how they define and limit driver interaction. For this, prior studies about HMI were reviewed and 15 participants performed an on-road study to drive vehicles from five manufacturers with using their interfaces. The results of the study confirmed that buttons and switches that are easily controlled by the user while driving were different from manufacturer to manufacturer. And there are some buttons that are more intensively controlled and others that are difficult to control while driving. It was able to derive 'selection and concentration' from Audi's vehicle, 'optimization of the driving ' from BMW's, 'simple and minimize' from Benz's vehicle, 'remove the manual distraction' from the vehicle of Lexus, and 'visual stability' from KIA's vehicle as the distinctive keywords for the HMI. This shows that each manufacturer has a different definition and interpretation of the driver's driving control area. This study has a distinct value in that it has identified the characteristics of vehicle-specific HMI in actual driving conditions, which is not apparent in appearance. It is expected that this research approach can be useful to see differences in interaction through actual driving despite changes in driving environment such as vehicle platooning and self-driving technology.

The influence of chemical water quality on fish trophic guilds, pollution tolerance, and multi-metric ecological health in the main streams of Mangyeong River (만경강 본류의 어류 트로픽 길드, 오염 내성도 및 다변수 생태건강도에 대한 화학적 수질영향)

  • Na, Hyun-Hee;Lee, Sang-Jae;An, Kwang-Guk
    • Korean Journal of Environmental Biology
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    • v.37 no.1
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    • pp.8-18
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    • 2019
  • The objectives of this study were to analyze the influence of chemical water quality on fish guilds, pollution tolerance and the multi-metric ecological health, based on the Fish Assessment Index (FAI) in the main stream of Mangyeong River between 2009-2016. The quality of water with specific conductivity, TP, and $NH_4-N$ got worse dramatically in the down region. During the study, a total of 50 species were collected and the most dominant species was Zacco platypus. Also known as tolerant species, accounted 22.9% of the total abundances, thus indicating a trophic degradation. The downstream region (S5) had the highest number of fish external abnormalities, indicating a degradation of ecological health, based on the fish assemblages. Pearson correlation analysis indicated that relative abundance of tolerant fish species and omnivore fish species had a significant positive correlation(r>0.30, p<0.05) with values of BOD, conductivity and $NH_4-N$. Whereas, the relative abundance of the sensitive species and insectivore species had a significant negative relations (r<-0.30, p<0.001) with the parameters. The mean obtained from the multi-metric fish model, based on the FAI of all sites was 47 (n=40). This indicated a "fair condition" in the ecological health, and the downstream regions (S3-S5) were judged as "bad condition", indicating an influence of the chemical degradation on the ecological health.

A Biomechanics-Based Ergonomic Analysis for Footware Development (풋웨어 개발을 위한 생체역학 기반 인간공학적 분석 : B-boy 신발 개발을 중심으로)

  • Hah, Chong-Ku;Jang, Young-Kwan;Kim, Jin-Hyun
    • Journal of Convergence for Information Technology
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    • v.9 no.8
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    • pp.140-147
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    • 2019
  • The purpose of this study is to find biomechanical parameters for optimal shoes production through an ergonomic usability assessment of five existing types of shoes preferred by B-BOY. Ten experts and ten non-experts participated in the experiment, and 12 infrared cameras (Qualis, Oqus), force plate (Kistler, 9286AA) and foot pressure plate (Zebris Gmbh, Zebris PDM-System) were used to obtain the data. The results of the study are as follows. First, P shoes with a friction coefficient of 0.38 and a free moment of 0.32 N/m/kg are desirable in terms of traction capability and safety. Second, on the cushion, it was found that the N shoes 2.51 N, sec/kg and non-expert, and 2.86 N and sec/kg were suitable. Third, it is deemed appropriate for C shoes with a forefoot average pressure of 10.11 KPa (right), 10.05 KPa (left), and V shoes with a rearfoot average pressure of 8.4 KPa (right) and 8.36 KPa (left). In conclusion, the combination of the structure and material of V shoes should be developed for traction and stability, N shoes for cushion, and walking balance for C and V shoes.

A Study on the Acceptance Factors of the Introduction of a Smart IoT Technology for Well-being Companion Animal (반려동물 웰빙을 위한 스마트 IoT 기술 도입 수용요인에 관한 연구)

  • Kang, Sung Kwang;Kim, Hoontae;Ji, Yong Gu;Lee, Jeongyoung
    • The Journal of Society for e-Business Studies
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    • v.24 no.2
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    • pp.143-163
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    • 2019
  • The purpose of this study is to identify acceptance factors and influencing factors of respondents' adoption of smart IoT technology to companion animal health based on the integrated technology acceptance model. Based on the previous studies, we constructed the hypotheses by defining the technical factors, social factors, control variables, and mediating variables (UTAUT), and set the hypotheses between the independent variables of each factor and the dependent intention. A research model was designed to verify the relationship between variables. We developed questionnaires on the items and verified them through data collected from 494 people. As a result, product design, quality of service, product performance, and quality service of technological factors had a significant effects on performance expectancy and effort expectancy. However, product safety, product function awareness, and product price did not significantly affect performance expectancy and effort expectancy. Social influence had significant effects on cognitive effect, welfare system, and welfare facilities. In conclusion, the comparative analysis of technical factors and social factors showed that social factors have more significant effects on welfare systems and facilities.

A Secure and Lightweight Authentication Scheme for Ambient Assisted Living Systems (전천 후 생활보조 시스템을 위한 안전하고 경량화 된 인증기법)

  • Yi, Myung-Kyu;Choi, Hyunchul;Whangbo, Taeg-Keun
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.19 no.4
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    • pp.77-83
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    • 2019
  • With the increase in population, the number of such senior citizens is increasing day by day. These senior citizens have a variety of care needs, but there are not enough health workers to look after them. Ambient Assisted Living (AAL) aims at ensuring the safety and health quality of the older adults and extending the number of years the senior citizens can live independently in an environment of their own preference. AAL provides a system comprising of smart devices, medical sensors, wireless networks, computer and software applications for healthcare monitoring. AAL can be used for various purposes like preventing, curing, and improving wellness and health conditions of older adults. While information security and privacy are critical to providing assurance that users of AAL systems are protected, few studies take into account this feature. In this paper, we propose a secure and lightweight authentication scheme for the AAL systems. The proposed authentication scheme not only supports several important security requirements needed by the AAL systems, but can also withstand various types of attacks. Also, the security analysis results are presented to show the proposed authentication scheme is more secure and efficient rather than existing authentication schemes.

A study on the Evaluation of Real-Time Map Update Technology for Automated Driving (자율주행 지원을 위한 정밀도로지도 갱신기술 평가를 위한 기준 도출 연구)

  • PARK, Yu-Kyung;KANG, Won-Pyung;CHOI, Ji-Eun;KIM, Byung-Ju
    • Journal of the Korean Association of Geographic Information Studies
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    • v.22 no.3
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    • pp.146-154
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    • 2019
  • Recently, a system has been developed and applied to establish and utilize HD maps through R&D. The biggest problem, however, is the lack of a proper HD map update system, which requires the development and adoption of such a system as soon as possible. In addition, in the case of updating HD maps for automated driving, integrity and accuracy of maps are required for safe driving, so an test of these technologies and data quality is required. In April 2018, the Ministry of Land, Infrastructure and Transport implemented a project to 'Develop Technology to Demonstrate and Share the Instant Road Change Detection and Update Technology for automated driving. This paper analyzed the technology for updating map based on the investigation and analysis of relevant technology trends for the development of integrated demonstration and sharing technology of road change rapid detection and updating map technology, and put forward the criteria for road change rapid detection, integrated quality verification of update technology. It is expected that the results of this study will contribute to quality assurance of HD maps that support safety driving for automated vehicles.

Investigation for the deformation behavior of the precast arch structure in the open-cut tunnel (개착식 터널 프리캐스트 아치 구조물의 변형 거동 연구)

  • Kim, Hak Joon;Lee, Gyu-Phil;Lim, Chul Won
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.21 no.1
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    • pp.93-113
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    • 2019
  • The behavior of the 3 hinged precast arch structure was investigated by comparing field measurements with numerical analyses performed for precast lining arch structures, which are widely used for the open-cut tunnel. According to the field measurements, the maximum vertical displacement occurred at the crown with upward displacements during the backfilling up to the crown of the arch and downward displacements at the backfill height above the crown. The final crown displacement was 19 mm upward from the original position. The horizontal displacement at the sidewall, which had a maximum horizontal displacement, occurred inward of the arch when compacting the backfill up to the crown and returned to the original position after completing the backfill construction. According to the analysis of displacement measurements, economical design is expected to be possible for precast arch structures compared to rigid concrete structures due to ground-structure interactions. Duncan model gave good results for the estimation of displacements and deformed shape of the tunnel according to the numerical analyses comparing with field measurements. The earth pressure coefficients calculated from the numerical analyses were 0.4 and 0.7 for the left and the right side of the tunnel respectively, which are agreed well with the eccentric load acting on the tunnel due to topographical condition and actual field measurements.

Performance Analysis of Pyrotechnic Devices on the Reliability of Thermal Batteries (열전지의 신뢰성에 미치는 파이로테크닉 부품의 특성분석)

  • Cheong, Hae-Won;Kang, Sung-Ho;Kim, Kiyoul;Cho, Jang-Hyeon;Ryu, Byungtae;Baek, Seung-Su
    • Journal of the Korean Society of Propulsion Engineers
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    • v.23 no.1
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    • pp.116-123
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    • 2019
  • Thermal batteries are also called molten-salt batteries as the electrolyte is mainly composed of molten salt. The molten-salt electrolyte is a solid that does not conduct electricity at room temperature, but when it is melted by a pyrotechnic heat source, it becomes an excellent ionic conductor. Thermal batteries are a kind of pyrotechnic battery because they operate only when the solid electrolyte is melted by the heat energy provided by pyrotechnic materials. Pyrotechnic components used in a thermal battery include heat sources, fuse strips, and an igniter. The reliability of these pyrotechnic components critically affects the reliability and performance of the battery that must supply electricity stably to guided munitions even under extreme environmental conditions. Different igniter types offer different advantages: notch-type igniters offer improved ignition probability, whereas film-type igniters offer improved safety. The addition of metal oxides to the heat paper could improve the burn rate, and the ignition reliability could be greatly improved by using it with a flame igniter at the same time. Using a two-step reduction process, high-purity Fe particles in coral form can be safely obtained.