• 제목/요약/키워드: technological failures

검색결과 28건 처리시간 0.026초

유선전화망 시대의 마지막 인공물, 시티폰의 출현과 몰락 : 실패한 기술 프로젝트의 흔적 찾기 (The Emergence and Decline of the City Phone Project : Finding trace of failed technology)

  • 오선실
    • 과학기술학연구
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    • 제9권2호
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    • pp.51-78
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    • 2009
  • 실패한 기술은 대체로 성공을 위한 끊임없는 도전 중에 발생하는 몇 차례의 필연적인 시행착오의 과정으로 그려지거나 혹은 성공한 기술과 대비시켜, 애초부터 실패할 조건들을 가진 일종의 병리적 기술로 취급된다. 이렇듯 실패라는 결과를 통해 재구성된 서술들은 흔히 실패한 기술이 한때 다양한 행위자들과 관계 맺으며 복잡한 기술 네트워크를 구성했었다는 사실을 망각한다. 결국 실패한 기술은 기술 구현에 실패했을 뿐 아니라 기술사에서 정당한 평가를 받는데도 실패하는 경우가 많다. 이 글은 한국 정보 통신 산업에서 가장 대표적인 실패로 기억되는 시티폰 프로젝트를 한국 정보 통신 산업의 토양 위에서 시작에서 종결까지 전 과정을 추적해, 시티폰 프로젝트가 구성했던 기술 네트워크를 복원하고자 시도한다. 이를 통해, 처음부터 저렴한 가격, 낮은 기술을 지향했던 시티폰 프로젝트가 다양한 행위자들의 이해관계가 만나는 지점에서 한시적으로나마 안정된 기술 네트워크를 구성했으며, 이후 각 행위자들의 기술에 대한 의미부여가 달라지면서 변화했음을 확인할 수 있을 것이다. 또한 실패로 종결된 시티폰 기술 네트워크의 붕괴가 기술적 한계보다는 기술표준에 대한 불확실성, 우발적 환경 변화에 기인한 것임을 보일 수 있을 것이다.

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Unsaturated Soil Mechanics for Slope Stability

  • Rahardjo, Harianto;Satyanaga, Alfrendo;Leong, Eng-Choon
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2007년 가을학술발표회
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    • pp.481-501
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    • 2007
  • Excessive rainfalls due to climatic changes can trigger an increase in rainfall-induced slope failures that pose real threats to both lives and properties. Many high slopes in residual soils could stand at a steep angle, but failed during or after rainfall. Commonly, these slopes have a deep groundwater table and negative pore-water pressures in the unsaturated zone above the groundwater table contribute to the shear strength of soil and consequently to factor of safety of the slope. Stability assessment of slope under rainfall requires information on rate of rainwater infiltration in the unsaturated zone and the resulting changes in pore-water pressure and shear strength of soil. This paper describes the application of unsaturated soil mechanics principles and theories in the assessment of rainfall effect on stability of slope through proper characterization of soil properties, measurement of negative pore-water pressures, seepage and slope stability analyses involving unsaturated and saturated soils. Factors controlling the rate of changes in factor of safety during rainfall and a preventive method to minimize infiltration are highlighted in this paper.

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HUMAN RELIABILITY ASSESSMENT IN CONTEXT

  • HOLLNAGEL ERIK
    • Nuclear Engineering and Technology
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    • 제37권2호
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    • pp.159-166
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    • 2005
  • Human reliability assessment (HRA) is conducted on the unspoken premise that 'human error' is a meaningful concept and that it can be associated with individual actions. The basis for this assumption it found in the origin of HRA, as a necessary extension of PSA to account for the impact of failures emanating from human actions. Although it was natural to model HRA on PSA, a large number of studies have shown that the premises are wrong, specifically that human and technological functions cannot be decomposed in the same manner. The general experience from accident studies also indicates that action failures are a function of the context, and that it is the variability of the context rather than the 'human error probability' that is the much sought for signal. Accepting this will have significant consequences for the way in which HRA, and ultimately also PSA, should be pursued.

개방형 혁신여건 조성을 통한 정부 R&D투자의 성과 제고 (Performance Improvement of Government R&D Investments Through Creating Open Innovation Conditions)

  • 김재홍
    • 디지털융복합연구
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    • 제8권2호
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    • pp.29-42
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    • 2010
  • 그동안 정부는 R&D투자의 성과 제고를 위해 R&D 시스템 내의 구조와 프로세스를 개선하는데 많은 노력을 기울여 왔다. 그러나 대내외 기술 환경이 급변하고 투자규모가 지속적으로 증가함에 따라, 정부 R&D 또한 다양한 외부자원의 활용을 통해서 규모의 수확을 이룰 수 있는 혁신적인 접근방법이 필요한 상황이다. 이러한 관점에서 '개방형 혁신'은 외부자원에 대한 흡수능력 (absorptive capacity)을 향상시키고, 다양한 혁신주체 간 협력과 참여를 제고시킬 수 있다는 점에서 '정부실패'의 가능성을 최소화 시킬 수 있다. 본 논문은 정부 R&D투자의 성과에 관한 선행연구와 정부정책을 평가하고, 개방형 혁신이 정부 R&D투자의 성과 제고에 기여할 수 있는 연계성을 보여주고 있다.

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Effects of edge crack on the vibration characteristics of delaminated beams

  • Liu, Yang;Shu, Dong W.
    • Structural Engineering and Mechanics
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    • 제53권4호
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    • pp.767-780
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    • 2015
  • Delaminations and cracks are common failures in structures. They may significantly reduce the stiffness of the structure and affect their vibration characteristics. In the present study, an analytical solution is developed to study the effect of an edge crack on the vibration characteristics of delaminated beams. The rotational spring model, the 'free mode' and 'constrained mode' assumptions in delamination vibration are adopted. This is the first study on how an edge crack affects the vibration characteristic of delaminated beams and new nondimensional parameters are developed accordingly. The crack may occur inside or outside the delaminated area and both cases are studied. Results show that the effect of delamination length and thickness-wise location on reducing the natural frequencies is aggravated by an increasing crack depth. The location of the crack also influences the effect of delamination, but such influence is different between crack occurring inside and outside the delaminated area. The difference of natural frequencies between 'free mode' and 'constrained mode' increases then decreases as the crack moves from one side of the delaminated region to the other side, peaking at the middle. The analytical results of this study can serve as the benchmark for FEM and other numerical solutions.

Vertical axis wind turbine types, efficiencies, and structural stability - A Review

  • Rehman, Shafiqur;Rafique, Muhammad M.;Alam, Md. Mahbub;Alhems, Luai M.
    • Wind and Structures
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    • 제29권1호
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    • pp.15-32
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    • 2019
  • Much advancement has been made in wind power due to modern technological developments. The wind energy technology is the world's fastest-growing energy option. More power can be generated from wind energy by the use of new design and techniques of wind energy machines. The geographical areas with suitable wind speed are more favorable and preferred for wind power deployment over other sources of energy generation. Today's wind turbines are mainly the horizontal axis wind turbines (HAWTs) and vertical axis wind turbines (VAWTs). HAWTs are commercially available in various sizes starting from a few kilowatts to multi-megawatts and are suitable for almost all applications, including both onshore and offshore deployment. On the other hand, VAWTs finds their places in small and residential wind applications. The objective of the present work is to review the technological development, available sizes, efficiencies, structural types, and structural stability of VAWTs. Structural stability and efficiencies of the VAWTS are found to be dependent on the structural shape and size.

The effect of ionizing radiation on robotic trajectory movement and electronic components

  • Sofia Coloma;Paul Espinosa Peralta;Violeta Redondo;Alejandro Morono;Rafael Vila;Manuel Ferre
    • Nuclear Engineering and Technology
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    • 제55권11호
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    • pp.4191-4203
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    • 2023
  • Robotics applications are greatly needed in hazardous locations, e.g., fusion and fission reactors, where robots must perform delicate and complex tasks under ionizing radiation conditions. The drawback is that some robotic parts, such as active electronics, are susceptible to radiation. It can lead to unexpected failures and early termination of the robotic operation. This paper analyses the ionizing radiation effect from 0.09 to 1.5 Gy/s in robotic components (microcontrollers, servo motors and temperature sensors). The first experiment compares the performance of various microcontroller types and their actuators and sensors, where different mitigation strategies are applied, such as using Radiation-Hardened (Rad-Hard) microcontrollers or shielding. The second and third experiments analyze the performance of a 3-Degrees of Freedom (DoF) robotic arm, evaluating its components' responses and trajectory. This study enhances our understanding and expands our knowledge regarding radiation's impact on robotic arms and components, which is useful for defining the best strategies for extending the robots' operational lifespan, especially when performing maintenance or inspection tasks in radiation environments.

Lessons from the Design of Innovation Systems for Rural Industrial Clusters in India

  • Abrol, Dinesh
    • 기술혁신연구
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    • 제12권2호
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    • pp.67-97
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    • 2004
  • Practical experience with technology implementation of the upgrading of very small village industries in India suggests that innovation failures are not merely a result of the lack of proper interaction between the users and suppliers of technologies under implementation, but also a result of adoption of the primitive conception of competitiveness in their practice of technology development. The approach of promoting the small producers to become individually competitive by using labour intensive, small-scale intermediate technologies is proving to be totally inadequate for the achievement of technological efficiency in a dynamic sense. Guided by a primitive notion of competitiveness, the suppliers of intermediated technologies are thus being led into limiting their technological efforts in the sectors of direct interest to the rural industrial clusters to the transitional objectives of mainly poverty alleviation. Consequently they have not been able to target the small producers of these village industries for the objectives of business growth. This paper posits that under competitive conditions the self-employed small producer has not only to come together for access to resources, but also has to emerge as a multi-sectoral collective of producers, co-operating in production. With the aim to draw lessons that are generic and have policy implications for the development of innovation systems for local economy based rural industrial clusters and value chains, the author analyses in this paper the experience of innovation in technological systems for the sectors of leather, fruits and vegetable processing and agro processing by the People's Science Movement with the help of the Ministry of Science and Technology and other sectoral ministries in India where rural poor were required to pool the resources and capabilities for raising the scale and scope of their collective production organization.

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소프트웨어 Fault Tolerance를 이용한 고장점 표정 (Fault Location Identification Using Software Fault Tolerance Technique)

  • 김원하;장용원;한승수
    • 대한전기학회논문지:전력기술부문A
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    • 제54권2호
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    • pp.73-78
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    • 2005
  • The management of technological systems will become increasingly complex. Safe and reliable software operation is a significant requirement for many types of system. So, with software fault tolerance, we want to prevent failures by tolerating faults whose occurrences are known when errors are detected. This paper presents a fault location algorithm for single-phase-to-ground faults on the teed circuit of a parallel transmission line using software fault tolerance technique. To find the fault location of transmission line, we have to solve the 3rd order transmission line equation. A significant improvement in the identification of the fault location was accomplished using the N-Version Programming (NVP) design paradigm. The delivered new algorithm has been tested with the simulation data obtained from the versatile EMTP simulator.

정보시스템 프로젝트의 위험요인에 대한 현업인력과 서비스제공인력과의 인식도 차이 (Perceptual Differences between IS Project Service Providers and Customers on Information System Project Risk Factors: a Koran case)

  • 이석준;조숙진;박정선;함유근;김용재
    • Journal of Information Technology Applications and Management
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    • 제14권3호
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    • pp.79-94
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    • 2007
  • Cases of botched information systems implementation have been surfaced due to poor IS project management and control. One major source of such failures is the perceptual difference between the participants of IS projects who should define potential risk factors well before considered IS projects are launched. Based on risk factors cited from prior works, this paper empirically examines the risk factors associated with IS service project management to analyze perceptual differences between the IS service providers and customers in Korea. Data analyses found significant differences in the area of scheduling/resource, technological newness, communications, and sponsorship/ownership while statistically significant differences were observed in eleven individual factors out of forty six risk factors. Risk factors are also ordered in terms of perceived importance to highlight the critical differences.

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