• Title/Summary/Keyword: Factors of Non-Use

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Production Efficiency Evaluation Considering Various Process Parameters (다양한 공정변수를 포함한 생산품의 효율성 평가방법에 관한 연구)

  • Kim, Chu;Cho, YongJu;Seo, Yoonho;Jo, Hyunjae
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.22 no.6
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    • pp.921-930
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    • 2013
  • From an economic perspective, an enterprise's business activity depends on the efficient use of corporate resources for generating profits. However, on the enterprise side, it is difficult to measure and evaluate the effective use of each resource. This paper suggests an alternative for eliminating process inefficiencies in the consolidation of competitive power in auto parts manufacturing company A. Multitudinous process variables from company A's raw materials-to-shipment process are configured as input resources, and a Data Envelopment Analysis(DEA) is carried out to determine economical benefit of said resources' operation, as well as how products are manufactured. The DEA model offers a non-parametric approach to measuring relative efficiency using input and output factors. Furthermore, AHP is used for logically deciding the importance of each evaluation factor. In general, DEA models have been used for measuring efficiency of the service and public sectors. However, this study focused on measuring the efficiency of SMEs production lines.

Slotted hydrofoil design optimization to minimize cavitation in amphibious aircraft application: A numerical simulation approach

  • Conesa, Fernando Roca;Liem, Rhea Patricia
    • Advances in aircraft and spacecraft science
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    • v.7 no.4
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    • pp.309-333
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    • 2020
  • The proposed study aims to numerically investigate the performance of hydrofoils in the context of amphibious aircraft application. In particular, we also study the effectiveness of a slotted hydrofoil in minimizing the cavitation phenomenon, to improve the overall water take-off performance of an amphibious aircraft. We use the ICON A5 as a base model for this study. First, we propose an approach to estimate the required hydrofoil surface area and to select the most suitable airfoil shape that can minimize cavitation, thus improving the hydrodynamic efficiency. Once the hydrofoil is selected, we perform 2D numerical studies of the hydrodynamic and cavitating characteristics of a non-slotted hydrofoil on ANSYS Fluent. In this work, we also propose to use a slotted hydrofoil to be a passive method to control the cavitation performance through the boundary layer control. Numerical results of several slotted configurations demonstrate notable improvement on the cavitation performance. We then perform a multiobjective optimization with a response surface model to simultaneously minimize the cavitation and maximize the hydrodynamic efficiency of the hydrofoil. The optimization takes the slot geometry, including the slot angle and lengths, as the design variables. In addition, a global sensitivity study has been carried and it shows that the slot widths are the more dominant factors.

High Speed Identification Method of RFID Tag (RFID 태그의 고속 인식 기법)

  • 이광재
    • Journal of the Institute of Convergence Signal Processing
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    • v.5 no.1
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    • pp.6-12
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    • 2004
  • Identification rate and time are very important in the identification of RFID tag, and the tag requires simple structure to use economically large quantity of tags. These factors make the MAC protocols of wired or wireless network environment result in different requirements. In the paper, we propose a method to apply spread spectrum scheme using orthogonal channel via Walsh function as the anti-collision communication system for the purpose of non-collision identification of multiple tags, and consider its property. The proposed system use two step identification. in the first step, collision is resolved via constructing to respond after specific delay time based on unique n, and conventional polling scheme follows in the second step.

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Factors Affecting Adherence to Pharmacotherapy in Children with Attention-Deficit Hyperactivity Disorder: A Retrospective Study (주의력결핍 과잉행동장애 아동의 약물치료 순응도에 영향을 미치는 요인 : 후향적 연구)

  • Kim, Yoon-Jung;Oh, So-Young;Lee, Ji-Ah;Moon, Su-Jin;Lee, Won-Hae;Bahn, Geon-Ho
    • Journal of the Korean Academy of Child and Adolescent Psychiatry
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    • v.21 no.3
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    • pp.174-181
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    • 2010
  • Objectives: To identify the factors affecting long-term adherence to methylphenidate treatment in children with attention-deficit hyperactivity disorder (ADHD). Methods: A retrospective medical record review of 239 ADHD patients (mean age $9.3{\pm}2.6$ years, range 6.0-17.4 years) who had visited the child and adolescent psychiatry clinic at a university hospital, in Seoul, Korea from March 2005 to February 2008. Subjects were diagnosed as ADHD based on the criteria set forth in the Diagnostic and Statistical Manual of Mental Disorders 4th edition, text revision version (DSM-IV-TR) and underwent neuropsychological tests including the continuous performance test (CPT). Treatment discontinuation was defined as the last prescription date when the medication possession rate (MPR) became less than 0.80. Subjects were divided into three groups and labeled as Group I, non-adherence without pharmacotherapy, Group II, non-adherence with short-term pharmacotherapy, and Group III, adherence with long-term pharmacotherapy. Results: Ninety (37.7%) patients were grouped as non-adherent (Groups I+II) and 149 (62.3%) as adherent (Group III). The adherence group exhibited lower intelligence, higher symptom severity, and a higher number of comorbid psychiatric disorders than controls. The use of stimulants was significantly associated with long-term adherence to treatment. Additionally, the duration of interval between the date of the first visit and the date of the first prescription was positively associated with long-term adherence. Conclusion: About two-thirds of patients diagnosed as ADHD adhered to the treatment six months after the first visit. With respect to patient evaluation and the development of treatment strategies, factors affecting early drop-out and longer follow-up must be considered.

An Analysis of the Roles of Experience in Information System Continuance (정보시스템의 지속적 사용에서 경험의 역할에 대한 분석)

  • Lee, Woong-Kyu
    • Asia pacific journal of information systems
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    • v.21 no.4
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    • pp.45-62
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    • 2011
  • The notion of information systems (IS) continuance has recently emerged as one of the most important research issues in the field of IS. A great deal of research has been conducted thus far on the basis of theories adapted from various disciplines including consumer behaviors and social psychology, in addition to theories regarding information technology (IT) acceptance. This previous body of knowledge provides a robust research framework that can already account for the determination of IS continuance; however, this research points to other, thus-far-unelucidated determinant factors such as habit, which were not included in traditional IT acceptance frameworks, and also re-emphasizes the importance of emotion-related constructs such as satisfaction in addition to conscious intention with rational beliefs such as usefulness. Experiences should also be considered one of the most important factors determining the characteristics of information system (IS) continuance and the features distinct from those determining IS acceptance, because more experienced users may have more opportunities for IS use, which would allow them more frequent use than would be available to less experienced or non-experienced users. Interestingly, experience has dual features that may contradictorily influence IS use. On one hand, attitudes predicated on direct experience have been shown to predict behavior better than attitudes from indirect experience or without experience; as more information is available, direct experience may render IS use a more salient behavior, and may also make IS use more accessible via memory. Therefore, experience may serve to intensify the relationship between IS use and conscious intention with evaluations, On the other hand, experience may culminate in the formation of habits: greater experience may also imply more frequent performance of the behavior, which may lead to the formation of habits, Hence, like experience, users' activation of an IS may be more dependent on habit-that is, unconscious automatic use without deliberation regarding the IS-and less dependent on conscious intentions, Furthermore, experiences can provide basic information necessary for satisfaction with the use of a specific IS, thus spurring the formation of both conscious intentions and unconscious habits, Whereas IT adoption Is a one-time decision, IS continuance may be a series of users' decisions and evaluations based on satisfaction with IS use. Moreover. habits also cannot be formed without satisfaction, even when a behavior is carried out repeatedly. Thus, experiences also play a critical role in satisfaction, as satisfaction is the consequence of direct experiences of actual behaviors. In particular, emotional experiences such as enjoyment can become as influential on IS use as are utilitarian experiences such as usefulness; this is especially true in light of the modern increase in membership-based hedonic systems - including online games, web-based social network services (SNS), blogs, and portals-all of which attempt to provide users with self-fulfilling value. Therefore, in order to understand more clearly the role of experiences in IS continuance, analysis must be conducted under a research framework that includes intentions, habits, and satisfaction, as experience may not only have duration-based moderating effects on the relationship between both intention and habit and the activation of IS use, but may also have content-based positive effects on satisfaction. This is consistent with the basic assumptions regarding the determining factors in IS continuance as suggested by Oritz de Guinea and Markus: consciousness, emotion, and habit. The principal objective of this study was to explore and assess the effects of experiences in IS continuance, with special consideration given to conscious intentions and unconscious habits, as well as satisfaction. IN service of this goal, along with a review of the relevant literature regarding the effects of experiences and habit on continuous IS use, this study suggested a research model that represents the roles of experience: its moderating role in the relationships of IS continuance with both conscious intention and unconscious habit, and its antecedent role in the development of satisfaction. For the validation of this research model. Korean university student users of 'Cyworld', one of the most influential social network services in South Korea, were surveyed, and the data were analyzed via partial least square (PLS) analysis to assess the implications of this study. In result most hypotheses in our research model were statistically supported with the exception of one. Although one hypothesis was not supported, the study's findings provide us with some important implications. First the role of experience in IS continuance differs from its role in IS acceptance. Second, the use of IS was explained by the dynamic balance between habit and intention. Third, the importance of satisfaction was confirmed from the perspective of IS continuance with experience.

A Study on the Effect of User Value on Smartwatch Digital HealthcareAcceptance Intention to Promote Digital Healthcare Venture Start Up (Digital Healthcare 벤처창업 촉진을 위한, 사용자 가치가 Smartwatch Digital Healthcare 수용의도에 미치는 영향 연구)

  • Eekseong Jin;soyoung Lee
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.18 no.2
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    • pp.35-52
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    • 2023
  • Recently, as the non-face-to-face environment has developed due to COVID-19 and environmental pollution, the importance of online digital healthcare is increasing, and venture start-ups and activities such as health care, telemedicine, and digital treatments are also actively underway. This study conducted the impact on the acceptability of digital healthcare smartwatches with an integrated approach of the expanded integrated technology acceptance model (UTAUT2) and the behavioral inference model (BRT). The most advanced integrated technology acceptance model for innovative technology acceptance research was used to identify major factors such as utility expectations, social effects, convenience, price barriers, lack of alternatives, and behavioral intentions. For the study, about 410 responses from ordinary people in their teens to 60s across the country were collected, and based on this, the hypothesis was verified using structural equations after testing reliability and validity of the data. SPSS 23 and AMOS 23 were used for research analysis. Studies have shown that personal innovation has a significant impact on the reasons for acceptance (use value, social impact, convenience of use), attitude, and non-use (price barriers, lack of alternatives, and barriers to use). These results are the same as the results of previous studies that confirmed the influence of the main value of innovative ICT on user acceptance intention. In addition, the reason for acceptance had a significant effect on attitude, but the effect of the reason for non-acceptance was not significant. It can be analyzed that consumers are interested in new ICT products and new services, but purchase them more carefully and selectively. This study has evolved from the acceptance analysis of general-purpose consumer innovation technology to the acceptance analysis of consumer value in smartwatch digital healthcare, which is a new and important area in the future. Industrially, it can contribute to the product's purchase and marketing. It is hoped that this study will contribute to increasing research in the digital healthcare sector, which will play an important role in our lives in the future, and that it will develop into in-depth factors that are more suitable for consumer value through integrated approach models and integrated analysis of consumer acceptance and non-acceptance.

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Lethality-Associated Factors in Deliberate Self-Poisoning

  • Choi, In Young;Kim, Sun-Young;Chang, Jhin Goo;Song, Hoo Rim;Kim, Woo Jung;Lee, Su Young;Kim, Hyun-Soo;Hong, Minha
    • Journal of the Korean Academy of Child and Adolescent Psychiatry
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    • v.32 no.1
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    • pp.17-27
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    • 2021
  • Objectives: Deliberate self-poisoning (DSP) is the most common suicide method and can be life-threatening. The purpose of this study was to investigate the factors related to the lethality of DSP and the characteristics of the adolescent group. Methods: A retrospective study was conducted on patients who had visited an academic hospital's regional emergency medical center between 2015 and 2018. The data reviewed through their medical records included sociodemographic factors, clinical variables, and psychiatric treatment. Four groups (Q1-Q4) were categorized by descriptive analysis using the risk-rescue rating scale. Results: A total of 491 patients were enrolled in this study. This study showed that high lethality had statistically significant associations with male sex, older age, admitting suicidal intentions, and the use of herbicides for suicide. Logistic regression analyses showed a significant association between high-lethality and female [odds ratio (OR)=0.50, 95% confidence interval (CI)=0.30-0.81, p=0.01], non-psychiatric drugs (over-the-counter drug: OR=2.49, 95% CI=1.08-5.74, p=0.03; herbicide: OR=8.65, 95% CI=3.91-19.13, p<0.01), and denial of suicide intent (OR=0.28, 95% CI=0.15-0.55, p<0.01). Conclusion: This study showed the clinical factors associated with the high lethality of DSP and suggested that efforts were needed to care for and thoroughly examine patients with DSP.

Neuro-fuzzy model of concrete exposed to various regimes combined with De-icing salts

  • Ghazy, Ahmed;Bassuoni, Mohamed. T.
    • Computers and Concrete
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    • v.21 no.6
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    • pp.649-659
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    • 2018
  • Adaptive neuro-fuzzy inference systems (ANFIS) can be efficient in modelling non-linear, complex and ambiguous behavior of cement-based materials undergoing combined damage factors of different forms (physical and chemical). The current work investigates the use of ANFIS to model the behavior (time of failure (TF)) of a wide range of concrete mixtures made with different types of cement (ordinary and portland limestone cement (PLC)) without or with supplementary cementitious materials (SCMs: fly ash and nanosilica) under various exposure regimes with the most widely used chloride-based de-icing salts (individual and combined). The results show that predictions of the ANFIS model were rational and accurate, with marginal errors not exceeding 3%. In addition, sensitivity analyses of physical penetrability (magnitude of intruding chloride) of concrete, amount of aluminate and interground limestone in cement and content of portlandite in the binder showed that the predictive trends of the model had good agreement with experimental results. Thus, this model may be reliably used to project the deterioration of customized concrete mixtures exposed to such aggressive conditions.

The Possibilities to use the Non- Destructive Testing on Diagnosing Wears of Wagon Chassis

  • Munkhtsetseg, T.
    • International Journal of Railway
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    • v.5 no.1
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    • pp.22-28
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    • 2012
  • This report is devoted to the problems of Mongolian Railway Transportation Safety such as high length of wagon service life, defects due to the more factors of exploitation, idle time, increase of faults, poor condition of repairing shops and more hand and mechanical operations and these conditions are quite difficult to meet the safety and reliability of increasing transportation from day to day. The paper discusses that the most optimum solution is diagnosing before occurring wear, breakdown, and defects on the basis of studying characteristics of structural material breakdown, residual methods of voltage, effects of material hardness and linear defects of a crystal net and the reform of machines is very important to implement it. It focuses the structures, characteristics of the material transportation and tests and analyses of the wagon cart which has to meet the traffic safety of wagons and slow and soft movement. The study is done on the wagon chassis which has to meet the traffic safety of luggage wagons.

An Integrated Mathematical Model for Supplier Selection

  • Asghari, Mohammad
    • Industrial Engineering and Management Systems
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    • v.13 no.1
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    • pp.29-42
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    • 2014
  • Extensive research has been conducted on supplier evaluation and selection as a strategic and crucial component of supply chain management in recent years. However, few articles in the previous literature have been dedicated to the use of fuzzy inference systems as an aid in decision-making. Therefore, this essay attempts to demonstrate the application of this method in evaluating suppliers, based on a comprehensive framework of qualitative and quantitative factors besides the effect of gradual coverage distance. The purpose of this study is to investigate the applicability of the numerous measures and metrics in a multi-objective optimization problem of the supply chain network design with the aim of managing the allocation of orders by coordinating the production lines to satisfy customers' demand. This work presents a dynamic non-linear programming model that examines the important aspects of the strategic planning of the manufacturing in supply chain. The effectiveness of the configured network is illustrated using a sample, following which an exact method is used to solve this multi-objective problem and confirm the validity of the model, and finally the results will be discussed and analyzed.