• Journal of Biosystems Engineering
• /
• 제42권2호
• /
• pp.75-79
• /
• 2017

The use of tractors to carry out agricultural work has played an important role in mechanizing the agricultural sector. A repairable mechanical system (such as an agricultural tractor) is subject to deterioration or failure. In this study, a regression model was used to predict the failure rate of a John Deere 3140 tractor. The machine failure pattern was carefully studied, and key factors affecting the failure rate were identified in five regions of the Khouzestan province. Through a questionnaire, data was obtained from farm records. This data was grouped into six sub-groups, according to the annual use hours (AUH) and the manner in which the tractors were stored. Results showed that AUH and storage policies affected failure rate slightly. With an increase in the age of the tractors, the failure rate in the tractors used for 1050-2000 hours annually and stored outdoors was higher than those used for 200-1000 hours annually and stored in sheds. When the tractors were of the same age, the slope of the curve in the 200-1000 annual use hours increased gradually and then rapidly, but failure rate in the 1050-2000 annual use hours was high from the beginning, and subsequent increase in this value was almost uniform. As a result, it can be said that with an increase in the annual use hours, the failure and breakdown rate in John Deere 3140 tractors rapidly increases, but maintenance conditions only slightly affect the failure and breakdown rate.

• 한국식생활문화학회지
• /
• 제34권4호
• /
• pp.424-431
• /
• 2019

The purpose of this study is to analyze and evaluate the key success factors for the fast food industry in the region of Lahore Pakistan. Fast food concept developed very speedily in the last few years in Lahore region. The success or failure of a fast food industry based on some factors like Physical environment, Brand-name, Food quality, Price, Taste, Promotional activity, Habitual consumption, Health threats, Consumer expectation, and Family meal. To identify which of these factors has a greater influence on consumer satisfaction, four fast food restaurants such as McDonald's, PIZZA HUT, KFC, and subway were targeted randomly. The proposed research is quantitative in nature and for data collection; a random sampling technique was used. A questionnaire survey answered by 273 people was considered in this research. Data have been analyzed through statistical techniques. It is observed that Brand name, Food quality, Physical environment, Health threats, Price, Family meals, Habitual consumption, and Consumer expectation showed significant impacts on Fast food industry compared to other factors evaluated herein.

• 한국지진공학회논문집
• /
• 제8권6호통권40호
• /
• pp.13-22
• /
• 2004

연성 계수는 반응수정계수(R)의 핵심구성요소로서 내진설계에서 중요한 역할을 하는 계수이다. 본 연구에서의 연성계수()는 단자유도 구조물의 연성계수()에 다자유도 보정계수()를 곱하여 평가하였다. 단자유도 시스템의 연성계수는 지진하중을 받는 단자유도 구조물의 변위 연성요구도와 주기에 따른 비선형 동적해석으로부터 산정하였다. 다자유도 시스템의 영향을 고려하기 위한 다자유도 보정계수()는 기존의 연구에 근거하여 제시하였다. 철골 연성 모멘트 골조의 연성계수를 평가하기 위하여, 구조물의 층수, 골조시스템(외곽골조, 분배골조), 붕괴 메카니즘(강-기둥 약-보, 약-기둥 강-보), 토질조건 및 지진구역을 변수로 하여 총 108개의 예제 구조물을 설계하였다. 구조물의 층수, 붕괴 메카니즘 및 토질조건은 연성계수에 큰 영향을 미치는 반면, 골조 시스템 및 지진구역은 연성계수에 영향을 미치지 않는 것으로 나타났다.

• Earthquakes and Structures
• /
• 제9권2호
• /
• pp.339-352
• /
• 2015

Ancient masonry towers constitute a relevant part of the cultural heritage of humanity. Their earthquake protection is a topic of great concern among researchers due to the strong damage suffered by these brittle and massive structures through the history. The identification of the seismic behavior and failure of towers under seismic loading is complex. This strongly depends on many factors such as soil characteristics, geometry, mechanical properties of masonry and heavy mass, as well as the earthquake frequency content. A deep understanding of these aspects is the key for the correct seismic vulnerability evaluation of towers and to design the most suitable retrofitting measure. Recent tendencies on the seismic retrofitting of historical structures by means of prestressing are related to the use of smart materials. The most famous cases of application of prestressing in towers were discussed. Compared to horizontal prestressing, vertical post-tensioning is aimed at improving the seismic behavior of towers by reducing damage with the application of an overall distribution of compressive stresses at key locations.

• Nuclear Engineering and Technology
• /
• 제36권5호
• /
• pp.430-449
• /
• 2004

A quantitative model for a control system that integrates human operators, systems, and their interactions is developed based on discrete functions. After identifying the major entities and the key factors that are important to each entity in the control system, a quantitative analysis to estimate the recovery failure probability from an abnormal state is performed. A numerical analysis based on assumed values of related variables shows that this model produces reasonable results. The concept of 'relative sensitivity' is introduced to identify the major factors affecting the reliability of the control system. The analysis shows that the hardware factor and the design factor of the instrumentation system have the highest relative sensitivities in this model. T도 probability of human operators performing incorrect actions, along with factors related to human operators, are also found to have high relative sensitivities. This model is applied to an analysis of the TMI-2 nuclear power plant accident and systematically explains how the accident took place.

• 한국디지털정책학회:학술대회논문집
• /
• 한국디지털정책학회 2006년도 추계학술대회
• /
• pp.11-18
• /
• 2006

The purpose of this paper is to find an appropriate policy for local government innovation step by step. In order to accomplish this purpose, we considered the characteristics and situation of Gumi city. Specifically, we analyzed the win-win strategy of the department for the largest local administration innovation. Finally, we found that the chief executive's leadership and other strategies such as the adjustment of the innovation propulsion system are key factors. Also, Managing the resistance to change appeared during the process of local administrative innovation is important . The failure of the policy for local government innovation is caused by the failure to manage the resistance Thus for government innovation to succeed, correct informal ion provision, comprehensive participation of public officials and effect ive management of resistance is necessary.

• Geomechanics and Engineering
• /
• 제15권5호
• /
• pp.1039-1046
• /
• 2018

This paper presents a limit analysis of the series of construction stages of shallow tunneling method by investigating their respective safety factors and failure mechanisms. A case study for one particular cross-section of Beijing Subway Line 7 is undertaken, with a focus on the effects of multiple soil layers and construction sequencing of dual tunnels. Results show that using the step-excavation technique can render a higher safety factor for the excavation of a tunnel compared to the entire cross-section being excavated all at once. The failure mechanisms for each different construction stage are discussed and corresponding key locations are suggested to monitor the safety during tunneling. Simultaneous excavation of dual tunnels in the same cross-section should be expressly avoided considering their potential negative interactions. The normal and shear forces as well as bending moment of the primary lining and locking anchor pipe are found to reach their maximum value at Stage 6, before closure of the primary lining. Designing these struts should consider the effects of different construction stages of shallow tunneling method.

• 디지털융복합연구
• /
• 제5권1호
• /
• pp.27-33
• /
• 2007

The purpose of this paper is to find an appropriate policy for local government innovation step by step. In order to accomplish this purpose, we considered the characteristics and situation of Gumi city. Specifically, we analyzed the win-win strategy of the department for the largest local administration innovation. Finally, we found that the chief executive's leadership and other strategies such as the adjustment of the innovation propulsion system are key factors. Also, Managing the resistance to change appeared during the process of local administrative innovation is important. The failure of the policy for local government innovation is caused by the failure to manage the resistance. Thus, for government innovation to succeed, correct information provision, comprehensive participation of public officials and effective management of resistance is necessary.

• Journal of Korean Biological Nursing Science
• /
• 제21권1호
• /
• pp.22-36
• /
• 2019

Purpose: Even though advanced heart failure (HF) severely affects the patient's health-related quality of life (HRQoL), there is little information regarding this issue. This review is aimed to describe the relevant clinical characteristics of patient with advanced HF and identify factors influencing HRQoL in these patients. Methods: Empirical articles were searched from electronic databases issued from January 2000 to June 2018 with using the key terms 'heart failure' and 'quality of life'. There were a total of 22 articles that met the inclusion criteria and were analyzed for this study. Results: First, nine studies among 22 studies clearly stated that their participants were samples of patients with advanced HF. Most reviewed studies showed the New York Heart Association (NYHA) class as the criteria for identifying advanced HF. Second, the level of HRQoL varied depending on the measurement tools utilized by the researchers. Third, the NYHA class, gender, and symptoms were mainly associated with HRQoL in patients with advanced HF. Also, nurse- or physician-led intervention, exercise, spiritual-focused intervention, and palliative care improved the HRQoL of the patients with advanced HF. Conclusion: This study found that the clear application of criteria for advanced HF and the development of advanced HF-specific HRQoL measurement was needed. Prospective studies should be considered for identifying differences in the levels and factors influencing HRQoL in patients with early stage or advanced HF to design patient-centered care.

• Steel and Composite Structures
• /
• 제11권4호
• /
• pp.273-290
• /
• 2011

In current ductility-based earthquake-resistant design, the estimation of design forces continues to be carried out with the application of response modification factors on elastic design spectra. It is well-known that the response modification factor (R) takes into account the force reduction, strength, redundancy, and damping of structural systems. The key components of the response modification factor (R) are force reduction ($R_{\mu}$) and strength ($R_S$) factors. However, the response modification and strength factors for structural systems presented in design codes were based on professional judgment and experiences. A numerical study has been accomplished to evaluate force reduction, strength, and response modification factors for special steel moment resisting frames. A total of 72 prototype steel frames were designed based on the recommendations given in the AISC Seismic Provisions and UBC Codes. Number of stories, soil profiles, seismic zone factors, framing systems, and failure mechanisms were considered as the design parameters that influence the response. The effects of the design parameters on force reduction ($R_{\mu}$), strength ($R_S$), and response modification (R) factors were studied. Based on the analysis results, these factors for special steel moment resisting frames are evaluated.