• 대한안전경영과학회지
• /
• 제21권4호
• /
• pp.67-74
• /
• 2019

Visual inspection is regarded as one of the critical activities for quality control in a manufacturing company. it is thus important to improve the performance of detecting a defective part or product. There are three probable working modes for visual inspection: fully automatic (by automatic machines), fully manual (by human operators), and semi-automatic (by collaboration between human operators and automatic machines). Most of the current studies on visual inspection have been focused on the improvement of automatic detection performance by developing a better automatic machine using computer vision technologies. However, there are still a range of situations where human operators should conduct visual inspection with/without automatic machines. In this situation, human operators'performance of visual inspection is significant to the successful quality control. However, visual inspection of components assembled into a mobile camera module belongs to those situations. This study aims to investigate human performance issues in visual inspection of the components, paying more attention to human errors. For this, Abstraction Hierarchy-based work domain modeling method was applied to examine a range of direct or indirect factors related to human errors and their relationships in the visual inspection of the components. Although this study was conducted in the context of manufacturing mobile camera modules, the proposed method would be easily generalized into other industries.

• 대한영양사협회학술지
• /
• 제24권3호
• /
• pp.231-245
• /
• 2018

This study was conducted to investigate the status of food allergy knowledge and management of the teachers and operators of child care facilities in the Daejeon Area. Surveys of 262 teachers and 50 operators of child care facilities in Dong-gu and Jung-gu in Daejeon were conducted. The prevalence of food allergies was found to be 3.6% (102 children). The average score of teachers in the anaphylaxis knowledge survey was $0.18{\pm}0.22$. Additionally, the needs for food allergy education among teachers and operators was 88.2% and 98%, respectively. The survey revealed that all child care facilities in this study provide food service menus to parents, but only 14 facilities (28%) provided alternative food to children with food allergies, and some of these 14 facilities did not provide adequate alternatives. To ensure the safety and healthy growth of children with food allergies, it is necessary to provide food allergy education to teachers and operators, as well as to establish safe food service and allergy management systems in all child care facilities.

• 대한인간공학회지
• /
• 제33권1호
• /
• pp.27-37
• /
• 2014

Objective: This study aims to improve human performance by analyzing the operators' tasks and providing input data on the composition of future SMART operators. Background: SMART is a nuclear reactor for export which needs operators who can satisfy both safety and economic feasibility. Therefore, this study is fundamental research on the composition of operators and this research analyzed SMART tasks in terms of human safety performance. Method: After analyzing 10 SMART EOG in hierarchical task analysis, this study classified task performance types according to task requirements of NUREG-0711 (Rev.3). Results: This study found the task frequency of SMART EOG and 12 operating task types. Conclusion: This study expects that human performance can be improved by analyzing the personal errors, which have the highest task frequency among 12 operating task types. Application: The results of this study can be applied as base data when licensing needs to be acquired.

• 한국안전학회지
• /
• 제28권1호
• /
• pp.81-87
• /
• 2013

Crane operators usually work with their necks bent forward in a seating position for a long period. They have complained of their musculoskeletal stress at their necks. The objective of this study was to find the level of stress at the neck when crane operators bend their neck forward during their work. Experiments were conducted in the laboratory where subjects bent their necks forward for 1 minute and took a rest for 0.5 minute and repeated this performance for 60 minutes. Subjective evaluation using Borg's CR-10 scale and electromyography (EMG) were used to check the level of the stress at the neck. Subjects reported that the level of pain at the end of 60 min. experiment was close to the extreme pain(level 8.95). The EMG level(amplitude) increased 80% on the average and the center frequency of EMG shifted to the lower frequency level which indicated fatigue of neck muscles. Thus, it was found that there is quite much neck stress for crane operators when they maintain their neck posture of bending forward for a long time during their work. This information will be a basis in searching for an intervention measure for the crane operators' neck stress.

• Kyungpook Mathematical Journal
• /
• 제48권1호
• /
• pp.15-24
• /
• 2008

Let $N{\geq}1$ and p > 1. Let ${\Omega}$ be a domain of $\mathbb{R}^N$. In this article we shall establish Kato's inequalities for quasilinear degenerate elliptic operators of the form $A_pu$ = divA(x,$\nabla$u) for $u{\in}K_p({\Omega})$, ), where $K_p({\Omega})$ is an admissible class and $A(x,\xi)\;:\;{\Omega}{\times}\mathbb{R}^N{\rightarrow}\mathbb{R}^N$ is a mapping satisfying some structural conditions. If p = 2 for example, then we have $K_2({\Omega})\;= \;\{u\;{\in}\;L_{loc}^1({\Omega})\;:\;\partial_ju,\;\partial_{j,k}^2u\;{\in}\;L_{loc}^1({\Omega})\;for\;j,k\;=\;1,2,{\cdots},N\}$. Then we shall prove that $A_p{\mid}u{\mid}\;\geq$ (sgn u) $A_pu$ and $A_pu^+\;\geq\;(sgn^+u)^{p-1}\;A_pu$ in D'(${\Omega}$) with $u\;\in\;K_p({\Omega})$. These inequalities are called Kato's inequalities provided that p = 2. The class of operators $A_p$ contains the so-called p-harmonic operators $L_p\;=\;div(\mid{{\nabla}u{\mid}^{p-2}{\nabla}u)$ for $A(x,\xi)={\mid}\xi{\mid}^{p-2}\xi$.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제6권12호
• /
• pp.3133-3151
• /
• 2012

The optimal price strategy selection of two bounded rational cognitive mobile virtual network operators (MVNOs) in a duopoly spectrum sharing market is investigated. The bounded rational operators dynamically compete to sell the leased spectrum to secondary users in order to maximize their profits. Meanwhile, the secondary users' heterogeneous preferences to rate and price are taken into consideration. The evolutionary game theory (EGT) is employed to model the dynamic price strategy selection of the MVNOs taking into account the response of the secondary users. The behavior dynamics and the evolutionary stable strategy (ESS) of the operators are derived via replicated dynamics. Furthermore, a reward and punishment mechanism is developed to optimize the performance of the operators. Numerical results show that the proposed evolutionary algorithm is convergent to the ESS, and the incentive mechanism increases the profits of the operators. It may provide some insight about the optimal price strategy selection for MVNOs in the next generation cognitive wireless networks.

• 충청수학회지
• /
• 제24권1호
• /
• pp.19-34
• /
• 2011

A bounded linear operator T on a complex Banach space X is said to have property (I) provided that T has Bishop's property (${\beta}$) and there exists an integer p > 0 such that for a closed subset F of ${\mathbb{C}}$ ${X_T}(F)={E_T}(F)=\bigcap_{{\lambda}{\in}{\mathbb{C}}{\backslash}F}(T-{\lambda})^PX$ for all closed sets $F{\subseteq}{\mathbb{C}}$, where $X_T$(F) denote the analytic spectral subspace and $E_T$(F) denote the algebraic spectral subspace of T. Easy examples are provided by normal operators and hyponormal operators in Hilbert spaces, and more generally, generalized scalar operators and subscalar operators in Banach spaces. In this paper, we prove that if T has property (I), then the quasi-nilpotent part $H_0$(T) of T is given by $$KerT^P=\{x{\in}X:r_T(x)=0\}={\bigcap_{{\lambda}{\neq}0}(T-{\lambda})^PX$$ for all sufficiently large integers p, where ${r_T(x)}=lim\;sup_{n{\rightarrow}{\infty}}{\parallel}T^nx{\parallel}^{\frac{1}{n}}$. We also prove that if T has property (I) and the spectrum ${\sigma}$(T) is finite, then T is algebraic. Finally, we prove that if $T{\in}L$(X) has property (I) and has decomposition property (${\delta}$) then T has a non-trivial invariant closed linear subspace.

• 농촌계획
• /
• 제25권3호
• /
• pp.89-102
• /
• 2019

This study was conducted to investigate priority recognition of experts and related facility operators in establishing policies for revitalizing agro-healing services. After reviewing related studies, 5 policy division and 19 detailed sector were drawn, including improving accessibility, improving promotion and information provision method, improved public relations and information provision, diversification of facility and program, financial support, and expansion of expert and specialized institutions. A questionnaire survey was conducted on agro-healing experts, agro-healing facility operators, social welfare experts, and social welfare facility operators. The AHP analysis indicated that agro-healing experts and facility operators had the highest priority in the division of expansion of expert and specialized institutions, while social welfare experts and facility operators had the highest priority in financial support. The IPA analysis was conducted to identify the priority of each policy sector. Respondents recognized above normal importance to policy divisions, but were relatively aware of the importance of improving accessibility, with overall satisfaction level appearing to be moderate. The results of this study are expected to provide useful information for establishing agro-healing policies and for establishing effective strategies.

• 한국유기농업학회지
• /
• 제29권3호
• /
• pp.397-414
• /
• 2021

As the agricultural population continues to age, the shortage of labor is worsening. To respond to this, Machinery Operators, those who work on behalf of farmers, are on demand. This study examines the cases in Imsil, Sunchang, and Namwon in Jeollabuk-do, where such agencies are in action, and analyzes the elements of their success and customer satisfaction. A survey was circulated among the farmers who used these agricultural agencies, and a total of 180 responses were submitted. A multiple regression analysis was conducted to prove our thesis. The study shows that the agricultural assistance provided by the Machinery Operators did help in ameliorating the shortage of labor, and resulted in high customer satisfaction. In particular, it was analyzed that Assurance and responsiveness had a significant positive effect on satisfaction. In addition, satisfaction was analyzed to fully mediate between service quality and intention to reuse. This study provides further support for the need to expand the institution of Machinery Operators and to encourage agricultural agencies in order to address the shortage of labor in rural areas due to aging.

• The Journal of Asian Finance, Economics and Business
• /
• 제10권1호
• /
• pp.157-167
• /
• 2023

The purpose of this research was to determine the degree to which Small-to-Medium Enterprise (SME) owners and operators in Mountain Province were willing to take on financial risk to invest in the capital markets as a potential additional source of income, as well as the extent to which these five indicator variables-particularly their income, expenses, financial goals, liquid cash, and insurance coverage-were influenced by demographic factors. The study used a quantitative approach and employed a descriptive survey research method. The results show that the SME Owners and Operators in Mountain Province have minimal knowledge of capital market investments which makes them moderate investors with a neutral level of financial risk tolerance toward capital market investment. Their marital status, net income, and educational attainment significantly influence their financial risk tolerance level. The respondents also believe that engaging in the capital markets will grow their businesses. Further, the extent of influence of Income, Expenses, Liquid Cash, and Insurance Cover on the financial risk tolerance of the SME owners and operators in Mountain Province a great extent; thus, making them careful in investing in the capital markets, and it is primarily affected by their Net Income. Consequently, the financial goals of SME owners and operators in Mountain Province have a vital role in their financial risk tolerance level.