• Tuberculosis and Respiratory Diseases
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• v.79 no.4
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• pp.248-256
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• 2016

Somatic mutations that lead to hyperactivation of epidermal growth factor receptor (EGFR) signaling are detected in approximately 50% of lung adenocarcinoma in people from the Far East population and tyrosine kinase inhibitors are now the standard first line treatment for advanced disease. They have led to a doubling of progression-free survival and an increase in overall survival by more than 2 years. However, emergence of resistant clones has become the primary cause for treatment failure, and has created a new challenge in the daily management of patients with EGFR mutations. Identification of mechanisms leading to inhibitor resistance has led to new therapeutic modalities, some of which have now been adapted for patients with unsuccessful tyrosine kinase inhibitor treatment. In this review, we describe mechanisms of tyrosine kinase inhibitor resistance and the available strategies to overcoming resistance.

• Geomechanics and Engineering
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• v.14 no.6
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• pp.571-580
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• 2018

The failure mechanism of tunnel roof is investigated with upper bound theorem of limit analysis. The stochastic settlement and nonlinear failure criterion are considered in the present analysis. For the collapse of tunnel roof, the surface settlement is estimated by the simplified stochastic medium theory. The failure curve expressions of collapse blocks in homogeneous and in layered soils are derived, and the effects of material parameters on the potential range of failure mechanisms are discussed. The results show that the material parameters of initial cohesion, nonlinear coefficient and unit weight have significant influences on the potential range of collapse block in homogeneous media. The proportion of collapse block increases as the initial cohesion increases, while decreases as the nonlinear coefficient and the unit weight increase. The ground surface settlement increases with the tunnel radius increasing, while the possible collapse proportion decreases with increase of the tunnel radius. In layered stratum, the study is investigated to analyze the effects of material parameters of different layered media on the proportion of possible collapse block.

• Journal of Applied Reliability
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• v.8 no.3
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• pp.113-124
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• 2008

In reliability engineering, failure reporting, analysis, and corrective action system (FRACAS) is an useful tool for effective failure reporting and related operations. FRACAS is generally mainly focused on implementation of its closed-loop process, but also includes various related information which has to be effectively managed such as failure types, failure modes, failure mechanisms, and corrective actions. In this study, we adopt and utilize the concept of process knowledge, and create it through abstraction of FRACAS information. At each step of closed-loop process, the necessary type of knowledge, priority and usability are clearly defined. This study also suggests corresponding management tools such as business process management system, knowledge management system, and their key elements and functions to deal with process knowledge. A prototype system using simple closed-loop process with its process knowledge is presented to demonstrate the feasibility of the proposed work.

• Nuclear Engineering and Technology
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• v.30 no.3
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• pp.273-286
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• 1998

As there has arisen a concern that failure of the high burnup fuel under the reactivity-insertion accident(RIA) may occur at the energy lower than the expected, fuel behavior under the rod ejection accident in a typical Westinghouse-designed 950 MWe PWR was analyzed by using the three dimensional nodal transient neutronics code, PANBOX2 and the transient fuel rod performance analysis code, FRAP-T6. Fuel failure criteria versus the burnup was conservatively derived taking into account available test data and the possible fuel failure mechanisms. The high burnup and longer cycle length fuel loading scheme of a peak rod turnup of 68 MWD/kgU was selected for the analysis. Except three dimensional core neutronics calculation, the analysis used the same core conditions and assumptions as the conventional zero dimensional analysis. Results of three dimensional analysis showed that the peak fuel enthalpy during the rod ejection accident is less than one third of that calculated by the conventional zero dimensional analysis methodology and the fraction of fuel failure in the core is less than 4 %. Therefore, it can be said that the current design limit of less than 10 percent fuel failure and maintaining the core coolable geometry would be adequately satisfied under the rod ejection accident, even though the conservative fuel failure criteria derived from the test data are applied.

• Journal of Distribution Science
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• v.22 no.2
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• pp.103-113
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• 2024

Purpose: With the popularity of artificial intelligence (AI) in the service industry and occurrence ofservice failures in AI-based services, understanding human-robot interaction issues in service failure situations is especially important. Some issues which deserve further empirical investigation are whether consumers can develop the same tolerance for chatbots after service failure as they have for human agents, and the relationship between agent type and tolerance is mediated by the mechanisms of perceived warmth and perceived competence. Research Design, Data, and Methodology: This research experimentally collected and analyzed data from 119 university students who had experienced chatbots service failures. Differences in tolerance towards human agents and chatbots after experiencing service failures were explored, with a further examination of the mediating pathways between this relationship via perceived warmth and perceived competence. Results: Consumers are more tolerant ofservice failure with chatbots compared to service failure with human agents. Significant mediation of the relationship between service agent and service failure tolerance by perceived competence, while perceived warmth has no significant mediating effect. Conclusions: This research enhances our understanding of AI-assisted services, human-computer interaction, improves the service functionality of existing smart devices, and deepens the understanding of the relationship between consumer responses and behaviors.

• The Journal of Korean Obstetrics and Gynecology
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• v.37 no.2
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• pp.120-134
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• 2024

Objectives: This research aimed at investigating the trends of acupuncture treatment for Recurrent Implantation Failure (RIF) patients in IVF. Methods: Studies were searched from PubMed, Cochrane Library, EMBASE, CNKI up to April 2024. Terms as 'Implantation failure', 'Recurrent implantation failure', 'Repeated implantation failure', 'RIF' and 'Acupuncture', 'Electroacupuncture', 'Needling' were used. Results: Of 136 screened, 10 studies are selected and analyzed. Studies were conducted using manual acupuncture and electroacupuncture. The results showed that acupuncture (electroacupuncture) treatment for RIF patients is effective in improving clinical pregnancy rate, endometrial blood flow, uterus morphology, endometrium thickness. The most frequently used acupoints were 三陰交 (SP6) and 子宮 (EX-CA1). Conclusions: Included studies showed that acupuncture (electroacupuncture) might have effect on RIF. Further research and meta-analysis should be conducted to verify its therapeutic mechanisms and safety.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.5
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• pp.835-842
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• 2002

In this paper, static and fatigue bending strengths and failure mechanisms of CFRP (carbon fiber reinforced plastics) laminates having impact damages have been evaluated. Composite laminates used for this experiment are CF/EPOXY orthotropy laminated plates, which have two-interfaces $[0^0_ 4/90^0_4]_{ sym}$. A steel ball launched by the air gun collides against CFRP laminates to generate impact damages. The damage growth during bending fatigue test is observed by the scanning acoustic microscope (SAM) and also, the fracture surfaces were observed by using the SEM (scanning electron microscope). In the case of impacted-side compression, fracture is propagated from the transverse crack generated near impact point. On the other hand, fracture is developed toward the impact point from the edge of interface-B delamination in the case of impacted-side tension. Eventually, failure mechanisms have been confirmed based on the observed delamination areas and fracture surfaces.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.2467-2470
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• 2003

In this paper, fault tolerant mechanisms are presented for a servo manipulator system designed to operate in a hot cell. A hot cell is a sealed and shielded room to handle radioactive materials, and it is dangerous for people to work in the hot cell. So, remote operations are necessary to handle radioactive materials in the hot cell. KAERI has developed a servo manipulator system to perform such remote operations. However, since electric components such as servo motors are weak to radiations, fault tolerant mechanisms have to be considered. For fault tolerance of the servo manipulator system, hardware and software redundancy have been considered. In case of hardware, radioactive resistant electric components such as cables and connectors have been adopted and motors driving a transport have been duplicated. In case of software, a reconfiguration algorithm accommodating one motor's failure has been developed. The algorithm uses redundant axis to recover the end effector's motion in spite of one motor's failure.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.39 no.3
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• pp.167-173
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• 2003

Many of researches regarding mechanical properties of composite materials are associated with humid environment and temperature. Especially the temperature is a very important factor influencing the design of thermoplastic composites. However, the effect of temperature on impact behavior of reinforced composites have not yet been fully explored. An approach which predicts critical fracture toughness G$_{IC}$ was performed by the impact test in this work. The main goal of this work is to study the effect of temperature and span of specimen supports on the results of Charpy impact test for GF/PE composite. The critical fracture energy and failure mechanism of GF/PE composites were investigated in the temperature range of $60^{\circ}C;to;-50^{\circ}C$ by the Charpy impact test. The critical fracture energy showed the maximum at the ambient temperature, and it tended to decrease as the temperature increased or decreased from the ambient temperature. The major failure mechanisms are the fiber matrix debonding, the fiber pull-out and/or delamination and the matrix deformation.n.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.37 no.3
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• pp.240-245
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• 2001

The tensile strength and failure mechanisms of glass fiber polypropylene (GF/PP) composites are investigated in the temperature range from ambient to 8$0^{\circ}C$. The tensile strength increases as fiber volume fraction ratio increase. The tensile strength shows a maximum at ambient temperature, and it tens to decrease as temperature goes up. Major failure mechanisms of GF/PP composites can be classified as fiber matrix debonding, fiber pull-out, delamination and matrix deformation.