• Title/Summary/Keyword: Factor of the Feasibility Analysis

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Rotordynamic Model Development and Critical Speed Estimation Through Modal Testing for the Rotor-Bearing System of a MW Class Large-Capacity Induction Motor (MW급 대용량 유도전동기 축계의 모드실험 기반 회전체 동역학 해석모델 수립 및 위험속도 예측)

  • Park, Jisu;Choi, Jae-Hak;Kim, Dong-Jun;Sim, Kyuho
    • Tribology and Lubricants
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    • v.36 no.5
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    • pp.279-289
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    • 2020
  • In this paper, a method is proposed for establishing an approximate prediction model of rotor-dynamics through modal testing. In particular, the proposed method is applicable to systems that cannot be established according to conventional methods owing to the absence of information regarding the dimensions and material of the rotor-bearing system. The proposed method is demonstrated by employing a motor dynamometer driven by a 1 MW class induction motor without dimension and material information. The proposed method comprises a total of seven steps, wherein an initial model is established by incorporating approximate dimensions and material information, and the model is improved on the basis of the natural frequency characteristics of the system. During model improvement, the modification factor is introduced for adjusting the elastic modulus and shear modulus of the system. Analysis of critical speed and imbalance response indicates that the separation margin is 67% and the maximum vibration amplitude is less than the amplitude limit of 0.032 mm under the API 611 standard, which means that the motor dynamometer can stably operate at a rated speed of 1800 rpm. Hence, the obtained results validate the feasibility of the proposed method. Furthermore, for broad usage, it is necessary to accordingly apply and validate the proposed method for various rotor-bearing systems.

Epidemiological Study on Breast Cancer Associated Risk Factors and Screening Practices among Women in the Holy City of Varanasi, Uttar Pradesh, India

  • Paul, Shatabdi;Solanki, Prem Prakash;Shahi, Uday Pratap;Srikrishna, Saripella
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.18
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    • pp.8163-8171
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    • 2016
  • Background: Breast cancer is the second most cause of death (1.38 million, 10.9% of all cancer) worldwide after lung cancer. In present study, we assess the knowledge, level of awareness of risk factors and screening practices especially breast self examination (BSE) among women, considering the non-feasibility of diagnostic tools such as mammography for breast screening techniques of breast cancer in the holy city Varanasi, Uttar Pradesh, India. Materials and Methods: A cross-sectional population based survey was conducted. The investigation tool adopted was self administrated questionnaire format. Data were analysed using SPSS 20 version and Chi square test to determine significant association between various education groups with awareness and knowledge, analysis of variance was applied in order to establish significance. Results: The attitude of participants in this study, among 560 women 500 (89%) responded (age group 18-65 years), 53.8% were married. The knowledge about BSE was very low (16%) and out of them 15.6% were practised BSE only once in life time. study shown that prominent age at which women achieve their parity was 20 yrs, among 500 participants 224 women have achieved their parity from age 18 to 30 yrs. Very well known awareness about risk factors of breast cancer were alcohol (64.6%), smoking (64%) and least known awareness risk factors were early menarche (17.2%) and use of red meat (23%). The recovery factors of breast cancer cases were doctors support (95%) and family support (94.5%) as most familiar responses of the holy city Varanasi. Conclusions: The study revealed that the awareness about risk factors and practised of BSE among women in Varanasi is extremely low in comparison with other cities and countries as well (Delhi, Mumbai, Himachal Pradesh, Turkey and Nigeria). However, doctors and health workers may promote the early diagnosis of breast cancer.

Biodistribution and PET imaging of [18F]FMISO in mousecolon cancer xenografted mice

  • Seelam, Sudhakara Reddy;Lee, Ji Youn;Kim, Young Joo;Lee, Yun-Sang;Jeong, Jae Min
    • Journal of Radiopharmaceuticals and Molecular Probes
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    • v.1 no.2
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    • pp.137-144
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    • 2015
  • Hypoxia is an important adverse prognostic factor for tumor progression and is a major cause of failure of radiation therapy. In case of short-term hypoxia, the metabolism can recover to normal, but if hypoxia persists, it causes irreversible cell damage and finally leads to death. So a hypoxia marker would be very useful in oncology. In particular, 2-nitroimidazole can be reduced to form a reactive chemical species, which can bind irreversibly to cell components in the absence of sufficient oxygen, thus, the development of radiolabeled nitroimidazole derivatives for the imaging of hypoxia remains an active field of research to improve cancer therapy result. 2-nitroimidazole based hypoxia marker, [$^{18}F$]FMISO holds promise for the evaluation of tumor hypoxia by Positron emission tomography (PET), at both global and local levels. In the present study, [$^{18}F$]FMISO was synthesized using an automatic synthesis module with high radiochemical purity (>99%) in 60 min. Immunohistochemical analysis using pimonidazole confirmed the presence of hypoxia in xenografted CT-26 tumor tissue. A biodistribution study in CT-26 xenografted mice showed that the increased tumor-to-muscle ratio and tumor-to-blood ratios from 10 to 120 min post-injection. In the PET study, [$^{18}F$]FMISO also showed increased tumor-to-muscle ratios from 10 to 120 min post-injection. In conclusion, this study demonstrates the feasibility and utility of [$^{18}F$]FMISO for imaging hypoxiain mouse colon cancer model using small animal PET.

Accessing motivations of DIY(Do-It-Yourself) clothes through online community (온라인 커뮤니티에 나타난 의복 DIY(Do-It-Yourself)의 동기)

  • Kim, Ji-Yeon;Lee, Kyu-Hye
    • Journal of the Korean Society of Costume
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    • v.64 no.4
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    • pp.176-187
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    • 2014
  • Although DIY(Do-It-Yourself) clothes are not popular in Korea, they continually reflect emerging DIY trends. Previous studies have approached the technical aspect of DIY clothes or have considered them only as an aspect of consumption tendencies. The purpose of this study is to look into online communities to investigate distinctive elements, which form the DIY clothing culture. Participant observation of texts and pictures from the online community's postings about DIY was conducted and used for the analysis. Research results showed that personal and social factors motivated DIY clothes. Personal motivations are comprised of factors such as practical creativity and personal enjoyment. Practical creativity occurred when someone wished to express aesthetics and personality in DIY clothes; personal enjoyment refers to the pleasure and utility that one feels when one makes DIY clothes. The social motivations were comprised of factors such as a desire to show off and to expand social exchanges. The desire to show off involved wearing DIY clothes and then finding satisfaction from reactions of people who notice it. The "expansion of exchanges" was not only about sharing information about DIY clothes in an online community but also about distributing or giving real goods (materials or tools for DIY clothes and finished goods) as gifts. Furthermore, some "DIYers" made DIY clothes sustainable by pursuing economic feasibility as an additional motivational factor. When they had expertise and commercial traits, they established businesses in the form of independent creative firms, transforming themselves from productive consumers to producers.

Adaptive Logarithmic Increase Congestion Control Algorithm for Satellite Networks

  • Shin, Minsu;Park, Mankyu;Oh, Deockgil;Kim, Byungchul;Lee, Jaeyong
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.8 no.8
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    • pp.2796-2813
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    • 2014
  • This paper presents a new algorithm called the adaptive logarithmic increase and adaptive decrease algorithm (A-LIAD), which mainly addresses the Round-Trip Time (RTT) fairness problem in satellite networks with a very high propagation delay as an alternative to the current TCP congestion control algorithm. We defined a new increasing function in the fashion of a logarithm depending on the increasing factor ${\alpha}$, which is different from the other logarithmic increase algorithm adopting a fixed value of ${\alpha}$ = 2 leading to a binary increase. In A-LIAD, the ${\alpha}$ value is derived in the RTT function through the analysis. With the modification of the increasing function applied for the congestion avoidance phase, a hybrid scheme is also presented for the slow start phase. From this hybrid scheme, we can avoid an overshooting problem during a slow start phase even without a SACK option. To verify the feasibility of the algorithm for deployment in a high-speed and long-distance network, several aspects are evaluated through an NS-2 simulation. We performed simulations for intra- and interfairness as well as utilization in different conditions of varying RTT, bandwidth, and PER. From these simulations, we showed that although A-LIAD is not the best in all aspects, it provides a competitive performance in almost all aspects, especially in the start-up and packet loss impact, and thus can be an alternative TCP congestion control algorithm for high BDP networks including a satellite network.

A Study on the Influence of systematization of Entertainment Company (연예매니지먼트 기업성과에 관한 영향 연구)

  • Park, Jeong-Bae;Shin, Phil-Soon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.11
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    • pp.5411-5416
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    • 2013
  • To verify confidence of the measurement such as Firm performance of Entertainment system, Cronbach's alpha coefficient were measured and showed 0.7 or higher alpha values. Feasibility of the measurement is also ensured by exploratory factor analysis. This thesis are formulated and analyzed as two little hypotheses to make certain that systematization of entertainment company influences on the performance. As a result, the two hypotheses are significant influential factors on the performance of entertainment company. The result are somewhat predicted because it was constructed by theories and preceding research which the researcher had already recognized. But this study was conducted to provide suggestions to establish a theory of entertainment industry by active follow-up studies for resolving will-less different results in this field due to a lack of the proceding research. And it is required to be established through the academic interchange among the similar studies.

Outcome of single-incision laparoscopic cholecystectomy compared to three-incision laparoscopic cholecystectomy for acute cholecystitis

  • Sanggyun Suh;Soyeon Choi;YoungRok Choi;Boram Lee;Jai Young Cho;Yoo-Seok Yoon;Ho-Seong Han
    • Annals of Hepato-Biliary-Pancreatic Surgery
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    • v.27 no.4
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    • pp.372-379
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    • 2023
  • Backgrounds/Aims: While single-incision laparoscopic cholecystectomy (SILC) has advantages in cosmesis and postoperative pain, its utilization has been limited. This study raises the possibility of expanding its indication to acute cholecystitis with the novel method of solo surgery under retrospective analysis. Methods: We compared the outcomes of SILC (n = 58) to those of three-incision laparoscopic cholecystectomy (TILC; n = 117) for acute cholecystitis, being performed from March 2014 to December 2015. Results: Intraoperative results, including the operation time, did not differ significantly, except for drain catheter insertion (p = 0.004). Each group had 1 case of open conversion due to common bile duct injury. There was no significant difference in the length of hospital stay. Either group by itself was not a risk factor for complications, but in preoperative drainage for intraoperative perforation, 3 factors of intraoperative perforation, biliary complication, and history of upper abdominal operation for additional port, only American Society of Anesthesiology (ASA) scores for postoperative complication of Clavien-Dindo grades III and IV were significant risk factors. Conclusions: Our study findings showed comparative outcomes between both groups, providing evidence for the safety and feasibility of SILC for acute cholecystitis.

The Fuelization Study on the Oil Palm Frond Through Torrefaction (Oil Palm Frond의 반탄화를 통한 연료화 연구)

  • Lee, Myung Suk;Jeong, Gwangsik;Jung, Sang-Jin;Lee, Kwan-Young
    • Korean Chemical Engineering Research
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    • v.51 no.4
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    • pp.465-469
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    • 2013
  • In this study, we investigated the feasibility of torrefied OPF (oil palm fronds) as the fuel. The torrefaction was performed at 200, 250, 300 and $350^{\circ}C$ during 1 and 2 hours, respectively. As raising the torrefaction temperature and increasing the processing time, the GHV (gross heating value) of torrefied OPFs was increased. Moreover, we found that the torrefaction temperature is more important factor than the processing time. However, the proper torrefaction temperature was asked because the higher torrefaction temperature leaded to the lower torrefied OPF yield. TGA (thermo-gravimetric analysis) data released that the torrefaction at $250^{\circ}C$ could significantly decompose the hemicellulose and the almost cellulose was decomposed at $300^{\circ}C$. In addition, the grindability of biomass was improved after torrefaction, so that it can reduce energy consumption in comminution.

Motivation of Mobile Shopping in Relation to Value of Shopping, Consumer Satisfaction, and Repurchase Intention (모바일 쇼핑동기, 쇼핑가치와 소비자만족도 및 재구매의도에 관한 연구)

  • Kim, Kyung-hee
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.22 no.10
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    • pp.1287-1293
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    • 2018
  • This study tested relationship between consumer's motivation for mobile shopping and their value of shopping, satisfaction, and repurchase intention. The result of the analysis deduced four factors in motivation for mobile shopping-: ubiquity, convenience, impulsiveness, and economic feasibility. The results indicated that motivation for mobile shopping and consumers' value of shopping have a significant influence on each other. Specifically, impulsiveness had a considerable influence on hedonic shopping value, whereas convenience had a significant influence on utilitarian shopping value. In addition, motivation for mobile shopping and value of shopping had a significant influence on consumer satisfaction and repurchase intention. To put it concretely, among the motives of mobile shopping, ubiquity is found to be the factor influencing consumer satisfaction and repurchase intention the most. Lastly, consumers' shopping value influences consumer satisfaction and revisiting intention significantly. This result provides useful base data for establishing distinctive marketing strategies in the rapidly growing mobile shopping market.

A Study on Port Efficiency in the Russian Arctic as a Key Factor for Trade Growth in the Northern Sea Route (북극항로 무역 성장을 위한 러시아 북극의 항만 효율화에 관한 연구)

  • Ilana Zakharova;Hyang-Sook Lee
    • Korea Trade Review
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    • v.48 no.4
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    • pp.121-148
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    • 2023
  • The rapid melting of Arctic sea ice has increased interest in the Northern Sea Route (NSR) as a viable alternative trade route between Europe and Asia. While extensive research has examined its competitiveness in terms of technical feasibility, safety, profitability, and environmental impact, the topic of the NSR ports remains relatively underrepresented in the literature. Hence, this study aims to contribute to the existing research by assessing the efficiency of 17 NSR ports to gain insights into their operations and identify areas for improvement using models of Data Envelopment Analysis(DEA). The obtained results show that efficient ports mainly belong to the western NSR region, with ports like Murmansk and Varandei consistently demonstrating high efficiency and constant returns to scale. Several ports, such as Onega, Arkhangelsk, Naryan-Mar, and Khatanga, showed inefficiencies in the utilization of berths and quay lengths. The findings not only contribute to academic knowledge but also offer practical implications for NSR port authorities, assisting them in making well-informed decisions regarding infrastructure development plans.