• 한국도로학회논문집
• /
• 제19권6호
• /
• pp.201-212
• /
• 2017

PURPOSES : The objective of this study is to identify the characteristics affecting traffic accidents that have occurred in 564 industrial complexes nationwide from 2011 to 2015. METHODS : The traffic accidents were specified using various factors such as industrial complex type (national VS. general), industrial complex degradation (old VS. non-old), location of complex (capital VS. non-capital), and traffic law violation (speeding, signal violation, and median invasion). The average number of crashes and accident ratio (fatal, severe, and both) in terms of characteristics of industrial complexes were calculated. With a sample of crashes of the industrial complexes for 5 years, statistical significances were tested to analyze and compare the differences based on industrial complex and traffic law characteristics using parametric and non-parametric methods. RESULTS : From statistical results, it is observed that the crash frequency occurring in old industrial complexes is three times higher than that in non-old industrial complexes. Old industrial complexes located in a capital area, old national industrial complexes, and old general industrial complexes are considerably related to higher crash frequency, but the fatal accident ratio appeared to have no statistical difference across industrial complex characteristics. Severe crashes are more likely to occur in non-old industrial complexes on an average. CONCLUSIONS : It is necessary to eliminate potential threats to roads and traffic in the same manner as illegal parking in industrial complexes through the restoration of old industrial complexes. To improve the efficiency of road infrastructure, efforts should be made to improve traffic safety in accordance with industrial characteristics such as planning and operation of relevant local government programs.

• 한국구조물진단유지관리공학회 논문집
• /
• 제19권6호
• /
• pp.55-62
• /
• 2015

공공시설물의 대형화 및 도심지로의 인구 밀집화에 따라 충돌 또는 폭발과 같은 하중조건 하에서의 구조물 방호성능의 중요성이 대두되고 있다. 그러나 구조물의 방호설계 및 시공에 있어서 필수적이라 할 수 있는 구조 재료 또는 자재에 대한 방호성능 평가기준은 현재 정립되어 있지 않은 실정이다. 따라서 본 연구에서는 구조용 자재의 내충격 성능평가 기준 개발 연구의 일환으로 가스건을 사용한 발사체 충격 파괴시험을 콘크리트 시험체에서 수행함과 동시에, 다양한 접촉식 계측 센서의 적용 가능성을 확인하고자 하였다. 또한, 충격 파괴시험을 통해 일반 콘크리트 및 강섬유가 보강된 초고성능콘크리트의 파괴모드 및 방호성능에 대한 평가를 수행하였다. 실험 수행 결과, 접촉식 계측센서 중 LVDT 변위계의 적용 가능성을 확인하였으며, UHPC의 경우 혼입된 보강섬유의 효과로 인해 일반 콘크리트에 비해 우수한 방호성능을 보여주었다.

• 산경연구논집
• /
• 제12권3호
• /
• pp.43-49
• /
• 2021

Purpose: This study attempted to examine the risk of stock price plunge according to the firm's management strategy. Prospector firms value innovation and have high uncertainties due to rapid growth. There is a possibility of lowering the quality of financial reporting in order to meet market expectations while withstanding the uncertainty of the results. In addition, managers of prospector firms enter into compensation contracts based on stock prices, thus creating an incentive to withhold negative information disclosure to the market. Prospector firms' information opacity and delays in disclosure of negative information are likely to cause a sharp decline in share prices in the future. Research design, data and methodology: This study performed logistic analysis of KOSPI listed firms from 2014 to 2017. The independent variable is the strategic index, and is calculated by considering the six characteristics (R&D investment, efficiency, growth potential, marketing, organizational stability, capital intensity) of the firm. The higher the total score, the more it is a firm that takes a prospector strategy, and the lower the total score, the more it is a firm that pursues a defender strategy. In the case of the dependent variable, a value of 1 was assigned when there was a week that experienced a sharp decline in stock prices, and 0 when it was not. Results: It was found that the more firms adopting the prospector strategy, the higher the risk of a sharp decline in the stock price. This is interpreted as the reason that firms pursuing a prospector strategy do not disclose negative information by being conscious of market investors while carrying out venture projects. In other words, compensation contracts based on uncertainty in the outcome of prospector firms and stock prices increase the opacity of information and are likely to cause a sharp decline in share prices. Conclusions: This study's analysis of the impact of management strategy on the stock price plunge suggests that investors need to consider the strategy that firms take in allocating resources. Firms need to be cautious in examining the impact of a particular strategy on the capital markets and implementing that strategy.

• 해양환경안전학회지
• /
• 제24권3호
• /
• pp.319-324
• /
• 2018

The collision problem is one of the design factors that must be carefully considered for the risk of collision occurring during the operation of ships and offshore structures. This paper presents the main results of the ship collision study, and its main goal is to analyze potential crash scenarios that may occur in the FLNG (Floating Liquefied Natural Gas) considering the likelihood and outcome. Consideration being given to vessels visiting the FLNG and surrounding vessels navigating around, such as functionally supported vessels and offloading carriers. The scope includes vessels visiting the FLNG facility such as in-field support vessels and off-loading carriers, as well as third party passing vessels. In this study, based on QRA (quantitative risk assessment), basic research methods and information on collision are provided. Based on the assumptions and methodologies documented in this study, it has been possible to clarify the frequency of collision and the damage category according to the type of visiting ship. Based on these results, the risk assessment results related to the collision have been derived.

• 자동차안전학회지
• /
• 제4권1호
• /
• pp.5-11
• /
• 2012

This paper discusses the evaluation of the safety impact of the Adaptive Cruise Control (ACC) system in Korea. To evaluate the safety impact, this paper suggests an analysis method by using the test scenario and field operational test data. The test scenario is composed to represent the main component factor of the ACC system and ACC related accident situation such as rear-end collision, lane-change, and road-curvature, etc. Also, from the field operation test data, the system's potential to increase the safety can be measured ideally. Besides, field operational testdata was used to revise the expected safety impact value as Korean road conditions. By using the proposed evaluation method, enhanced safety impact of the ACC system can be estimated scientifically.

• 한국공작기계학회:학술대회논문집
• /
• 한국공작기계학회 2000년도 춘계학술대회논문집 - 한국공작기계학회
• /
• pp.403-408
• /
• 2000

The use of tailor welded blanks(TWB) in automotive applications is increasing due to the potential of weight and cost saving In this study, the front side member of passenger car is developed by typical analysis and crash simulations. According this results, energy absorption and barrier force is very important to control passenger safety and deformation shape. For that purpose, it is most effective to absorb energy more tailor welded blanks front side member than non-twb. The front side member with twb is simulated, in which reduced stamping parts, weight reduction and cost down.

• Nuclear Engineering and Technology
• /
• 제53권9호
• /
• pp.3068-3084
• /
• 2021

Investigations of large commercial aircraft impact effect on nuclear power plant (NPP) buildings have been drawing extensive attentions, particularly after the 9/11 event, and this paper aims to experimentally assess the damage and vibrations of NPP buildings subjected to aircraft crash. In present Part I, two shots of reduce-scaled model test of aircraft impacting on NPP building were carried out. Firstly, the 1:15 aircraft model (weighs 135 kg) and RC NPP model (weighs about 70 t) are designed and prepared. Then, based on the large rocket sled loading test platform, the aircraft models were accelerated to impact perpendicularly on the two sides of NPP model, i.e., containment and auxiliary buildings, with a velocity of about 170 m/s. The strain-time histories of rebars within the impact area and acceleration-time histories of each floor of NPP model are derived from the pre-arranged twenty-one strain gauges and twenty tri-axial accelerometers, and the whole impact processes were recorded by three high-speed cameras. The local penetration and perforation failure modes occurred respectively in the collision scenarios of containment and auxiliary buildings, and some suggestions for the NPP design are given. The maximum acceleration in the 1:15 scaled tests is 1785.73 g, and thus the corresponding maximum resultant acceleration in a prototype impact might be about 119 g, which poses a potential threat to the nuclear equipment. Furthermore, it was found that the nonlinear decrease of vibrations along the height was well reflected by the variations of both the maximum resultant vibrations and Cumulative Absolute Velocity (CAV). The present experimental work on the damage and dynamic responses of NPP structure under aircraft impact is firstly presented, which could provide a benchmark basis for further safety assessments of prototype NPP structure as well as inner systems and components against aircraft crash.

• 한국분말재료학회지
• /
• 제10권6호
• /
• pp.383-389
• /
• 2003

As in other areas of materials technology, the tendency towards light weight constructions becomes more and more important also for powder metallurgy. The development is mainly driven by the automotive industry looking for mass reduction of vehicles as a major factor for fuel economy. Powder metallurgy has to offer a number of interesting areas including the development of sintered materials of light metals. PM aluminium alloys with improved properties are on the way to replace ferrous pars. For high temperature applications in the engine, titanium aluminide based materials offer a great potential, e.g. for exhaust valves. The PM route using elemental powders and reactions sintering is considered to be a cost effective way for net shape parts production. Furthermore it is expected that lower costs for titanium raw materials coming from metallurgical activities will offer new chances for sintered parts with titanium alloys. The field of cellular metals expands with the hollow sphere technique, that can provide materials of many metals and alloys with a great flexibility in structure modifications. These structures are expected to be used in improving the safety (crash absoption) and noise reduction in cars in the near future and offer great potential for many other applications.

• 국제학술발표논문집
• /
• The 9th International Conference on Construction Engineering and Project Management
• /
• pp.579-586
• /
• 2022

Modular building is a fast-growing construction method, mainly due to its ability to drastically reduce the amount of time it takes to construct a building and produce higher-quality buildings at a more consistent rate. However, while modular construction is relatively safer than traditional construction methods, workers are still exposed to hazards that lead to injuries and fatalities, and these hazards could be controlled using emerging smart technologies. Currently, limited information is available at the intersection of modular construction, safety risk, and smart safety technologies. This paper aims to investigate what aspects of modular construction are most dangerous for its workers, highlight specific risks in its processes, and propose ways to utilize smart technologies to mitigate these safety risks. Findings from the archival analysis of accident reports in Occupational Safety and Health Administration (OSHA) Fatality and Catastrophe Investigation Summaries indicate that 114 significant injuries were reported between 2002 and 2021, of which 67 were fatalities. About 72% of fatalities occurred during the installation phase, while 57% were caused by crushing and 85% of crash-related incidents were caused by jack failure/slippage. IoT-enabled wearable sensing devices, computer vision, smart safety harness, and Augment and Virtual Reality were identified as potential solutions for mitigating identified safety risks. The present study contributes to knowledge by identifying important safety trends, critical safety risk factors and proposing practical emerging methods for controlling these risks.

• 한국ITS학회 논문지
• /
• 제22권3호
• /
• pp.73-87
• /
• 2023

교통안전정보를 제공하는 서비스는 운전자에게 도로의 위험상황을 미리 전달함으로써 교통사고 예방에 도움을 줄 수 있다. 이에 다양한 센서로 도로 상황을 즉각적으로 인지하고 적절한 교통안전정보를 제공하는 스마트 도로조명 플랫폼 개발 연구가 진행되고 있다. 본 연구는 Surrogate Safety Measures (SSM)를 활용하여 스마트 도로조명의 터널 교통안전정보 제공 서비스 운영에 대한 단기적인 교통 안전성 개선 효과를 분석하였다. 분석에 활용된 자료는 강릉시 안인피암 1, 2 터널구간에서 레이더 검지기를 이용하여 수집된 차량 궤적자료이며, 이를 통해 개별 차량의 주행행태를 분석하였다. 교통안전정보 제공 사전과 사후의 과속, 속도 변동, 충돌예상시간, 충돌회피 감속도를 비교한 결과, 모든 SSM이 통계적으로 유의하게 개선되어 터널 교통안전정보 제공 서비스가 교통안전 향상에 효과적인 것으로 나타났다. 터널구간과 접속구간을 세분화하여 사고 위험성을 분석한 결과, 교통안전정보 제공 시 대부분의 구간에서 교통사고 발생 가능성이 저하된 것이 확인되었다. 본 연구는 교통안전정보 제공 서비스에 대한 단기 효과분석으로 유익한 사례가 될 수 있을 것으로 기대된다.