• 제목/요약/키워드: Time-varying Failure

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A Study on CRM Practices for Public sector Insurance Companies

  • Dinesh, Reetha
    • Asia-Pacific Journal of Business
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    • v.3 no.1
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    • pp.39-47
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    • 2012
  • Organizations pursue a CRM strategy for the purpose of increasing business performance and value. However, firms face a multitude of organizational challenges associated with this endeavor. To reduce their risk of failure, it is suggested that firms undertake a deep analysis of organizational readiness prior to committing to a CRM initiative. Insurance sector is no exception to this fact. There is an increased need to concentrate on the various challenges thrown open by the public insurance firms in implementing CRM. Many insurance firms have invested into customer driven CRM but research indicates varying outcomes (Schmith 2004). While it is clear that there are significant issues involved in the CRM implementation and success and environment faced by the public sector. It is clear that business should have an easier time in applying CRM systems is the strategic value for public sector. With customers demanding more service and accessibility from administrators, public sector CRM software technologies have to offer best solutions for achieving process and cost objectives (Souder 2001). With results which go far beyond improved service delivery and include sustained cost reductions, increased customer knowledge and better employee morale, CRM software implementation and post product environments offer great upside value. Although there are material differences in public sector use of CRM strategy, they share at least one glaring similarity - they have much to gain from proven CRM software technology. As business methods cross over in the public sector, many government bodies are investigating how they can adopt and adapt various CRM models (Bleyer 2003). There is a need to understand the similarities and differences in public sector CRM to foster shared knowledge, business processes and planning functions to integrate disparate technologies and software platforms and then, of course, the organizational culture to support knowledge sharing (Peters 1997). For the public sector, there are clearly identified CRM processes which have resulted in increased profits and improved efficiency. These have focused on sales, marketing and customer service activities, which often operate along fundamentally different lines in various public sector insurance companies. Thus the present research paper makes an attempt to explore how public sector CRM methods can be adopted and subsequently adapted.

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Development of reliable $H_\infty$ controller design algorithm for singular systems with failures (고장 특이시스템의 신뢰 $H_\infty$ 제어기 설계 알고리듬 개발)

  • 김종해
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.41 no.4
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    • pp.29-37
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    • 2004
  • This paper provides a reliable H$_{\infty}$ state feedback controller design method for delayed singular systems with actuator failures occurred within the prescribed subset. The sufficient condition for the existence of a reliable H$_{\infty}$ controller and the controller design method are presented by linear matrix inequality(LMI), singular value decomposition, Schur complements, and changes of variables. The proposed controller guarantees not only asymptotic stability but also H$_{\infty}$ norm bound in spite of existence of actuator failures. Since the obtained sufficient condition can be expressed as an LMI fen all variables can be calculated simultaneously. Moreover, the controller design method can be extended to the problem of robust reliable H$_{\infty}$ controller design method for singular systems with parameter uncertainties, time-varying delay, and actuator failures. A numerical example is given to illustrate the validity of the result.

Adverse effect of IL-6 on the in vitro maturation of porcine oocytes

  • Yi, Young-Joo;Adikari, Adikari Arachchige Dilki Indrachapa;Moon, Seung-Tae;Heo, Jung-Min;Lee, Sang-Myeong
    • Korean Journal of Agricultural Science
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    • v.48 no.3
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    • pp.607-615
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    • 2021
  • Cytokines are protein mediators that possess the ability to assist cell-to-cell communication in immune system-related activities. In general, pathogen endotoxins activate the release of inflammatory mediators, and with time, there is an increase in the cytokine levels in the body. Interleukin (IL)-6 mediates the acute-phase inflammatory response, and elevated IL-6 levels have been reported in peritoneal fluids of women with pelvic inflammation and endometriosis, thereby associating it with oocyte quality and infertility. To overcome subfertility or infertility in humans and animals, the present study was done to examine the effect of recombinant IL-6 on porcine oocytes matured in vitro and subsequently to determine the fertilization rate and embryo development. Porcine oocytes were incubated with varying concentrations of IL-6 (0 - 2 ㎍·mL-1) for 44 h followed by in vitro fertilization and culturing of the oocytes. The oocytes or embryos were fixed with 3.7% paraformaldehyde (PFA) and stained with fluorescence dyes, and the meiotic spindle, chromosome organization, fertilization status and embryo development were subsequently assessed under a fluorescence microscope. We observed induction of an abnormal meiotic spindle alignment in the oocytes incubated with IL-6 compared to the control oocytes incubated without IL-6. Moreover, significantly decreased fertilization rates and embryo development were observed for oocytes incubated with IL-6 (p < 0.05). Thus, an increased IL-6 level during oocyte maturation could be associated with fertilization failure due to an aberrant chromosomal alignment and a disruption of the cortical granules. Taken together, our results indicate that successful assisted reproduction can be achieved by controlling the levels of inflammatory cytokines.

Development of a Stochastic Snow Depth Prediction Model Using a Bayesian Deep Learning Method (베이지안 딥러닝 기법을 이용한 확률적 적설심 예측 모델 개발)

  • Jeong, Youngjoon;Lee, Sang-ik;Lee, Jonghyuk;Seo, Byunghun;Kim, Dongsu;Seo, Yejin;Choi, Won
    • Journal of The Korean Society of Agricultural Engineers
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    • v.64 no.6
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    • pp.35-41
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    • 2022
  • Heavy snow damage can be prevented in advance with an appropriate security system. To develop the security system, we developed a model that predicts snow depth after a few hours when the snow depth is observed, and utilized it to calculate a failure probability with various types of greenhouses and observed snow depth data. We compared the Markov chain model and Bayesian long short-term memory models with varying input data. Markov chain model showed the worst performance, and the models that used only past snow depth data outperformed the models that used other weather data with snow depth (temperature, humidity, wind speed). Also, the models that utilized 1-hour past data outperformed the models that utilized 3-hour data and 6-hour data. Finally, the Bayesian LSTM model that uses 1-hour snow depth data was selected to predict snow depth. We compared the selected model and the shifting method, which uses present data as future data without prediction, and the model outperformed the shifting method when predicting data after 11-24 hours.

Observation of Muscle Activity and Muscle Fatigue During Isotonic Exercise at a Constant Face Using Metronome (메트로놈을 사용한 일정한 페이스의 등장성 운동시 근활성도 및 근육 피로도 관찰)

  • Jun won Choi;Chang hyun Song;Jong min Kim;Woon Mo Jung;Won Gyeong Kim;Han Sung Kim
    • Journal of Biomedical Engineering Research
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    • v.44 no.4
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    • pp.284-292
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    • 2023
  • This study attempted to observe muscle activity and muscle fatigue among isotonic exercise of Biceps Brachii and Deltoidus Medius, which correspond to upper limb muscles, using metronome. For the experiment, 13 adult men participated to evaluate biosignals (ECG, EMG). For quantitative evaluation, 1RM and MVIC test were carried out and a constant pace isotonic excise session was conducted. Five sets of exercise were performed, and each set proceeded to the failure point while the speed condition (30bpm) was assigned. As a result of the experiment, muscle activity in both muscles was significantly reduced in fifth set compared to first set. Muscle fatigue has been confirmed to occur at a significant level within the set, but there was only a significant difference in both muscles in the first and second sets between sets. This is similar to the results of previous studies that gives the same rest time(2min), but further research is needed to see if the conditions for the number of repetitions are affected. Based on the recent increase of interest in muscle strength exercise, this study was conducted to observe the results by varying the conditions of common exercise.

Assessment of the characteristics of ferro-geopolymer composite box beams under flexure

  • Dharmar Sakkarai;Nagan Soundarapandian
    • Advances in concrete construction
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    • v.15 no.4
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    • pp.251-267
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    • 2023
  • In this paper, an experimental investigation is carried out to assess the inherent self-compacting properties of geopolymer mortar and its impact on flexural strength of thin-walled ferro-geopolymer box beam. The inherent self-compacting properties of the optimal mix of normal geopolymer mortar was studied and compared with self-compacting cement mortar. To assess the flexural strength of box beams, a total of 3 box beams of size 1500 mm × 200 mm × 150 mm consisting of one ferro-cement box beam having a wall thickness of 40 mm utilizing self-compacting cement mortar and two ferro-geopolymer box beams with geopolymer mortar by varying the wall thickness between 40 mm and 50 mm were moulded. The ferro-cement box beam was cured in water and ferro-geopolymer box beams were cured in heat chamber at 75℃ - 80℃ for 24 hours. After curing, the specimens are subjected to flexural testing by applying load at one-third points. The result shows that the ultimate load carrying capacity of ferro-geopolymer and ferro-cement box beams are almost equal. In addition, the stiffness of the ferro-geoploymer box beam is reduced by 18.50% when compared to ferro-cement box beam. Simultaneously, the ductility index and energy absorption capacity are increased by 88.24% and 30.15%, respectively. It is also observed that the load carrying capacity and stiffness of ferro-geopolymer box beams decreases when the wall thickness is increased. At the same time, the ductility and energy absorption capacity increased by 17.50% and 8.25%, respectively. Moreover, all of the examined beams displayed a shear failure pattern.

Research on unsupervised condition monitoring method of pump-type machinery in nuclear power plant

  • Jiyu Zhang;Hong Xia;Zhichao Wang;Yihu Zhu;Yin Fu
    • Nuclear Engineering and Technology
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    • v.56 no.6
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    • pp.2220-2238
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    • 2024
  • As a typical active equipment, pump machinery is widely used in nuclear power plants. Although the mechanism of pump machinery in nuclear power plants is similar to that of conventional pumps, the safety and reliability requirements of nuclear pumps are higher in complex operating environments. Once there is significant performance degradation or failure, it may cause huge security risks and economic losses. There are many pumps mechanical parameters, and it is very important to explore the correlation between multi-dimensional variables and condition. Therefore, a condition monitoring model based on Deep Denoising Autoencoder (DDAE) is constructed in this paper. This model not only ensures low false positive rate, but also realizes early abnormal monitoring and location. In order to alleviate the influence of parameter time-varying effect on the model in long-term monitoring, this paper combined equidistant sampling strategy and DDAE model to enhance the monitoring efficiency. By using the simulation data of reactor coolant pump and the actual centrifugal pump data, the monitoring and positioning capabilities of the proposed scheme under normal and abnormal conditions were verified. This paper has important reference significance for improving the intelligent operation and maintenance efficiency of nuclear power plants.

A Model for the Optimal Mission Allocation of Naval Warship Based on Absorbing Markov Chain Simulation (흡수 마코프 체인 시뮬레이션 기반 최적 함정 임무 할당 모형)

  • Kim, Seong-Woo;Choi, Kyung-Hwan
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.22 no.6
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    • pp.558-565
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    • 2021
  • The Republic of Korea Navy has deployed naval fleets in the East, West, and South seas to effectively respond to threats from North Korea and its neighbors. However, it is difficult to allocate proper missions due to high uncertainties, such as the year of introduction for the ship, the number of mission days completed, arms capabilities, crew shift times, and the failure rate of the ship. For this reason, there is an increasing proportion of expenses, or mission alerts with high fatigue in the number of workers and traps. In this paper, we present a simulation model that can optimize the assignment of naval vessels' missions by using a continuous time absorbing Markov chain that is easy to model and that can analyze complex phenomena with varying event rates over time. A numerical analysis model allows us to determine the optimal mission durations and warship quantities to maintain the target operating rates, and we find that allocating optimal warships for each mission reduces unnecessary alerts and reduces crew fatigue and failures. This model is significant in that it can be expanded to various fields, not only for assignment of duties but also for calculation of appropriate requirements and for inventory analysis.

The Experimental Study on the Bond behavior of High strength concrete (고강도 콘크리트의 부착거동에 관한 실험적 연구)

  • Lee, Joon-Gu;Kim, Woo;Park, Kwang-Su;Kim, Dae-Joung;Lee, Wong-Chan;Kim, Han-Joung
    • Proceedings of the Korea Concrete Institute Conference
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    • 1999.04a
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    • pp.774-780
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    • 1999
  • The study of bond behavior between concrete and rebar has been performed for a long time. On this study, we tried to analysed variation of bond behaviors quantitatively with varying the strength of concrete. Bond stress which observed below the neutral surface of beam and at connecting part of beam and column is affected by various bond parameters. Resistance of deformed bars which embedded in concrete to the pullout force is divided 1) chemical adhesive force 2) frictional force 3) mechanical resistance of ribs to the concrete and these horizontal components of resistance is being bond strength. We selected the most common and typical variable which is concrete strength among various variables. So we used two kinds of concrete strength like as 25MPa(NSC) and 65MPa(HSC). Tension Test was performed to verify how bond behavior varied with two kinds of concrete strength. Concentration of bond stress was observed at load-end commonly in Tension Test of the initial load stage. At this stage stress distribution was almost coincident at each strength. As tension load added, this stress distribution had difference gradually and movement of pick point of bond stress to free-end and central section was observed. This tendency was observed at first and moving speed was more fast in NSC. At the preceeding result the reason of this phenomenon is considered to discretion of chemical adhesion and local failure of concrete around rebar in load-end direction. Especially, when concrete strength was increased 2.6 times in tension test, ultimate bond strength was increased 1.45 times. In most recent used building codes, bond strength is proportioned to sqare root of concrete compressive strength but comparison of normalized ultimate bond strength was considered that the higher concrete strength is, the lower safety factor of bond strength is in each strength if we use existing building codes. In Tension Test, in case of initial tensile force state, steel tensile stress of central cross section is not different greatly at each strength but tensile force increasing, that of central cross section in NSC was increased remarkably. Namely, tensile force which was shared in concrete in HSC was far greater than that of concrete in NSC at central section.

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Comparison of Prediction Accuracy Between Classification and Convolution Algorithm in Fault Diagnosis of Rotatory Machines at Varying Speed (회전수가 변하는 기기의 고장진단에 있어서 특성 기반 분류와 합성곱 기반 알고리즘의 예측 정확도 비교)

  • Moon, Ki-Yeong;Kim, Hyung-Jin;Hwang, Se-Yun;Lee, Jang Hyun
    • Journal of Navigation and Port Research
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    • v.46 no.3
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    • pp.280-288
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    • 2022
  • This study examined the diagnostics of abnormalities and faults of equipment, whose rotational speed changes even during regular operation. The purpose of this study was to suggest a procedure that can properly apply machine learning to the time series data, comprising non-stationary characteristics as the rotational speed changes. Anomaly and fault diagnosis was performed using machine learning: k-Nearest Neighbor (k-NN), Support Vector Machine (SVM), and Random Forest. To compare the diagnostic accuracy, an autoencoder was used for anomaly detection and a convolution based Conv1D was additionally used for fault diagnosis. Feature vectors comprising statistical and frequency attributes were extracted, and normalization & dimensional reduction were applied to the extracted feature vectors. Changes in the diagnostic accuracy of machine learning according to feature selection, normalization, and dimensional reduction are explained. The hyperparameter optimization process and the layered structure are also described for each algorithm. Finally, results show that machine learning can accurately diagnose the failure of a variable-rotation machine under the appropriate feature treatment, although the convolution algorithms have been widely applied to the considered problem.