• Title/Summary/Keyword: Indirect Feedback

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Migration of Workers' Knowledge into Information Systems : Managerial Issues from the Case of e-Procurement Service Company (조직원 지식의 정보 시스템 이전 : 전자 구매 서비스 기업 사례를 통한 관리적 함의)

  • Jung, Gwangjae;Shim, Seonyoung
    • The Journal of Society for e-Business Studies
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    • v.18 no.2
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    • pp.47-67
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    • 2013
  • With the emergence of indirect procurement, it has become a global trend for companies to outsource their maintenance, repair, and operating (MRO) supplies to procurement service providers (PSPs). Due to the variety of MRO items, evaluation of numerous suppliers in various industries is a particularly complex task for PSPs. Due to this complexity, many PSPs still evaluate and select suppliers based on the sourcing managers' subjective knowledge. Through the case of adopting a supplier evaluation system, this research is to find the managerial issues organizations should consider when they transform sourcing managers' knowledge into the system. We interpret the issues based on the Technology-Organization-Environment (TOE) framework. This case conclusively shows the importance of positive feedback loop between the users and the information system for the performance improvement of the system.

Kalman Filter Design For Aided INS Considering Gyroscope Mixed Random Errors (자이로의 불규칙 혼합잡음을 고려한 보조항법시스템 칼만 필터 설계)

  • Seong, Sang-Man
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.34 no.4
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    • pp.47-52
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    • 2006
  • Using the equivalent ARMA model representation of the mixed random errors, we propose Klaman filter design methods for aided INS(Inertial Navigation System) which contains the gyroscope mixed random errors. At first step, considering the characteristic of indirect feedback Kalman filter used in the aided INS, we perform the time difference of equivalent ARMA model. Next, according to the order of the time differenced ARMA model, we achieve the state space conversion of that by two methods. If the order of AR part is greater than MA part, we use controllable or observable canonical form. Otherwise, we establish the state apace equation via the method that several step ahead predicts are included in the state variable, where we can derive high and low order models depending on the variable which is compensated from gyroscope output. At final step, we include the state space equation of gyroscope mixed random errors into aided INS Kalman filter model. Through the simulation, we show that both the high and low order filter models proposed give less navigation errors compared to the conventional filter which assume the mixed random errors as white noise.

A Study on the Structural Equation Model for Factors Affecting Academic Achievement in Non-Face-to-Face Class (비대면수업에서 학습성취도에 미치는 요인에 대한 구조방정식 모형 연구)

  • Suh, Hyesun
    • The Journal of the Convergence on Culture Technology
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    • v.6 no.4
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    • pp.157-164
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    • 2020
  • In 2020, due to COVID-19, all universities in Korea were conducting non-face-to-face classes. The purpose of this study is to study what factors affect academic achievement under such non-face-to-face instruction, especially for engineering students where practical training is important. Validity of the statistical hypothesis defined in this study by applying a structural equation model using questionnaires about academic achievement for engineering students at University D for this study. In addition, I would like to suggest what factors should be considered in non-face-to-face classes, especially in engineering colleges. As a result of the study, it was found that students' Q&A, feedback and e-learning system had a direct influence on academic achievement. In addition, it was confirmed that they had an indirect influence on academic achievement through the parameters of theory class and practical class.

Underwater Hybrid Navigation System Based on an Inertial Sensor and a Doppler Velocity Log Using Indirect Feedback Kalman Filter (간접 되먹임 필터를 이용한 관성센서 및 초음파 속도센서 기반의 수중 복합항법 시스템)

  • Lee, Chong-Moo;Lee, Pan-Mook;Seong, Woo-Jae
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2003.05a
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    • pp.149-156
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    • 2003
  • This paper presents an underwater hybrid navigation system for a semi-autonomous underwater vehicle (SAUV). The navigation system consists of an inertial measurement unit (IMU), an ultra-short baseline (USBL) acoustic navigation sensor and a doppler velocity log (DVL) accompanying a magnetic compass. The errors of inertial measurement units increase with time due to the bias errors of gyros and accelerometers. A navigational system model is derived to include the error model of the USBL acoustic navigation sensor and the scale effect and bias errors of the DVL, of which the state equation composed of the navigation states and sensor parameters is 25 in the order. The conventional extended Kalman filter was used to propagate the error covariance, update the measurement errors and correct the state equation when the measurements are available. Simulation was performed with the 6-d.o.f. equations of motion of SAUV in a lawn-mowing survey mode. The hybrid underwater navigation system shows good tracking performance by updating the error covariance and correcting the system's states with the measurement errors from a DVL, a magnetic compass and a depth senor. The error of the estimated position still slowly drifts in horizontal plane about 3.5m for 500 seconds, which could be eliminated with the help of additional USBL information.

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A Study on Startups' Dependence on Business Incubation Centers (창업보육서비스에 따른 입주기업의 창업보육센터 의존도에 관한 연구)

  • Park, JaeSung;Lee, Chul;Kim, JaeJon
    • Korean small business review
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    • v.31 no.2
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    • pp.103-120
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    • 2009
  • As business incubation centers (BICs) have been operating for more than 10 years in Korea, many early stage startups tend to use the services provided by the incubating centers. BICs in Korea have accumulated the knowledge and experience in the past ten years and their services have been considerably improved. The business incubating service has three facets : (1) business infrastructure service, (2) direct service, and (3) indirect service. The mission of BICs is to provide the early stage entrepreneurs with the incubating service in a limited period time to help them grow strong enough to survive the fierce competition after graduating from the incubation. However, the incubating services sometimes fail to foster the independence of new startup companies, and raise the dependence of many companies on BICs. Thus, the dependence on BICs is a very important factor to understand the survival of the incubated startup companies after graduation from BICs. The purpose of this study is to identify the main factors that influence the firm's dependence on BICs and to characterize the relationships among the identified factors. The business incubating service is a core construct of this study. It includes various activities and resources, such as offering the physical facilities, legal service, and connecting them with outside organizations. These services are extensive and take various forms. They are provided by BICs directly or indirectly. Past studies have identified various incubating services and classify them in different ways. Based on the past studies, we classify the business incubating service into three categories as mentioned above : (1) business infrastructure support, (2) direct support, and (3) networking support. The business infrastructure support is to provide the essential resources to start the business, such as physical facilities. The direct support is to offer the business resources available in the BICs, such as human, technical, and administrational resources. Finally, the indirect service was to support the resource in the outside of business incubation center. Dependence is generally defined as the degree to which a client firm needs the resources provided by the service provider in order to achieve its goals. Dependence is generated when a firm recognizes the benefits of interacting with its counterpart. Hence, the more positive outcomes a firm derives from its relationship with the partner, the more dependent on the partner the firm must inevitably become. In business incubating, as a resident firm is incubated in longer period, we can predict that her dependence on BICs would be stronger. In order to foster the independence of the incubated firms, BICs have to be able to manipulate the provision of their services to control the firms' dependence on BICs. Based on the above discussion, the research model for relationships between dependence and its affecting factors was developed. We surveyed the companies residing in BICs to test our research model. The instrument of our study was modified, in part, on the basis of previous relevant studies. For the purposes of testing reliability and validity, preliminary testing was conducted with firms that were residing in BICs and incubated by the BICs in the region of Gwangju and Jeonnam. The questionnaire was modified in accordance with the pre-test feedback. We mailed to all of the firms that had been incubated by the BICs with the help of business incubating managers of each BIC. The survey was conducted over a three week period. Gifts (of approximately ₩10,000 value) were offered to all actively participating respondents. The incubating period was reported by the business incubating managers, and it was transformed using natural logarithms. A total of 180 firms participated in the survey. However, we excluded 4 cases due to a lack of consistency using reversed items in the answers of the companies, and 176 cases were used for the analysis. We acknowledge that 176 samples may not be sufficient to conduct regression analyses with 5 research variables in our study. Each variable was measured through multiple items. We conducted an exploratory factor analysis to assess their unidimensionality. In an effort to test the construct validity of the instruments, a principal component factor analysis was conducted with Varimax rotation. The items correspond well to each singular factor, demonstrating a high degree of convergent validity. As the factor loadings for a variable (or factor) are higher than the factor loadings for the other variables, the instrument's discriminant validity is shown to be clear. Each factor was extracted as expected, which explained 70.97, 66.321, and 52.97 percent, respectively, of the total variance each with eigen values greater than 1.000. The internal consistency reliability of the variables was evaluated by computing Cronbach's alphas. The Cronbach's alpha values of the variables, which ranged from 0.717 to 0.950, were all securely over 0.700, which is satisfactory. The reliability and validity of the research variables are all, therefore, considered acceptable. The effects of dependence were assessed using a regression analysis. The Pearson correlations were calculated for the variables, measured by interval or ratio scales. Potential multicollinearity among the antecedents was evaluated prior to the multiple regression analysis, as some of the variables were significantly correlated with others (e.g., direct service and indirect service). Although several variables show the evidence of significant correlations, their tolerance values range between 0.334 and 0.613, thereby demonstrating that multicollinearity is not a likely threat to the parameter estimates. Checking some basic assumptions for the regression analyses, we decided to conduct multiple regression analyses and moderated regression analyses to test the given hypotheses. The results of the regression analyses indicate that the regression model is significant at p < 0.001 (F = 44.260), and that the predictors of the research model explain 42.6 percent of the total variance. Hypotheses 1, 2, and 3 address the relationships between the dependence of the incubated firms and the business incubating services. Business infrastructure service, direct service, and indirect service are all significantly related with dependence (β = 0.300, p < 0.001; β = 0.230, p < 0.001; β = 0.226, p < 0.001), thus supporting Hypotheses 1, 2, and 3. When the incubating period is the moderator and dependence is the dependent variable, the addition of the interaction terms with the antecedents to the regression equation yielded a significant increase in R2 (F change = 2.789, p < 0.05). In particular, direct service and indirect service exert different effects on dependence. Hence, the results support Hypotheses 5 and 6. This study provides several strategies and specific calls to action for BICs, based on our empirical findings. Business infrastructure service has more effect on the firm's dependence than the other two services. The introduction of an additional high charge rate for a graduated but allowed to stay in the BIC is a basic and legitimate condition for the BIC to control the firm's dependence. We detected the differential effects of direct and indirect services on the firm's dependence. The firms with long incubating period are more sensitive to indirect service positively, and more sensitive to direct service negatively, when assessing their levels of dependence. This implies that BICs must develop a strategy on the basis of a firm's incubating period. Last but not least, it would be valuable to discover other important variables that influence the firm's dependence in the future studies. Moreover, future studies to explain the independence of startup companies in BICs would also be valuable.

On-line Fundamental Frequency Tracking Method for Harmonic Signal and Application to ANC (조화신호의 실시간 기본 주파수 추종 방법과 능동소음제어에의 응용)

  • Kim, Sun-Min;Park, Young-Jin
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2000.06a
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    • pp.263-268
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    • 2000
  • In this paper, a new indirect feedback active noise control (ANC) scheme based on the fundamental frequency estimation is proposed for systems with a harmonic noise. When reference signals necessary for feedforward ANC configuration is difficult to obtain, the conventional ANC algorithms for multi-tonal noise do not measure the reference signals but generate them with the estimated frequencies. However, the beating phenomena, in which certain frequency components of the noise vanish intermittently, may make the adaptive frequency estimation difficult. The confusion in the estimated frequencies due to the beating phenomena makes the generated reference signals worthless. The proposed algorithm consists of two parts. The first part is a reference generator using the fundamental frequency estimation and the second one is the conventional feedforward control. We propose the fundamental frequency estimation algorithm using decision rules, which is insensitive to the beating phenomena. In addition, the proposed fundamental frequency estimation algorithm has good tracking capability and lower variance of frequency estimation error than that of the conventional cascade ANF method. We are also able to control all interested modes of the noise, even which cannot be estimated by the conventional frequency estimation method because of the poor SIN ratio. We verify the performance of the proposed ANC method through simulations for the measured cabin noise of a passenger ship and the measured time-varying engine booming noise of a passenger vehicle.

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Active Control of Harmonic Signal Based on On-line Fundamental Frequency Tracking Method (실시간 기본주파수 추종방법에 근간한 조화 신호의 능동제어)

  • 김선민;박영진
    • Journal of KSNVE
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    • v.10 no.6
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    • pp.1059-1066
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    • 2000
  • In this paper. a new indirect feedback active noise control (ANC) scheme barred on the fundamental frequency estimation is proposed for systems with a harmonic noise. When reference signals necessary for feedforward ANC configuration are difficult to obtain, the conventional ANC algorithms for multi-tonal noise do not measure the reference signals but generate them with the estimated frequencies.$^{(4)}$ However, the beating phenomena, in which certain frequency components of the noise vanish intermittently, may make the adaptive frequency estimation difficult. The confusion in the estimated frequencies due to the beating phenomena makes the generated reference signals worthless. The proposed algorithm consists of two parts. The first part is a reference generator using the fundamental frequency estimation and the second one is the conventional feedforward control. We propose the fundamental frequency estimation algorithm using decision rules. which is insensitive to the beating phenomena. In addition, the proposed fundamental frequency estimation algorithm has good tracking capability and lower variance of frequency estimation error than that of the conventional cascade ANF method.$^{(4)}$ We are also able to control all interested modes of the noise, even which cannot be estimated by the conventional frequency estimation method because of the poor S/N ratio. We verify the performance of the proposed ANC method through simulations for the measured cabin noise of a passenger ship and the measured time-varying engine booming noise of a passenger vehicle.

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A Study on Effect of Social support on Baby boomer's Entrepreneurial Opportunity Competence: Focusing on Mediating Effect of Entrepreneurial Self-Efficacy (사회적지지가 베이비부머의 창업기회역량에 미치는 영향에 관한 연구: 창업자기효능감의 매개효과를 중심으로)

  • Kim, Sang Soo;Lim, Wang Kyu
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.12 no.5
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    • pp.101-115
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    • 2017
  • This study analyzed the effects of social support on entrepreneurial opportunity competence for Baby boomer (born in 1955-1963), focusing on mediating effect of entrepreneurial self-efficacy. The governmental start-up policy and entrepreneurship education are mostly conducted for the college students and young generation mainly through such programs as the youth start-up school. In addition, studies on the effects of social support and institutional support on the entrepreneurial intention of young generation entrepreneurs are being actively pursued. Meanwhile, the study for baby boomers is on the welfare side mainly. Although they are starting to make their living-based business without prior careful preparation for their livelihood after retirement, while there is little study on the effect of social support for this baby boomer on entrepreneurial opportunity competence needed for opportunistic entrepreneurship. Therefore, in this study, in order to investigate the effect of social support on Baby boomer's entrepreneurial opportunity competence, an empirical analysis of the 387 questionnaires collected by the baby boomers living in Seoul and Gyeonggi provinces were conducted. As a result of analysis, First, Social support has a significant effect on both Opportunity recognition and Opportunity assessment of entrepreneurial opportunity competence. Second, In the effects of social support on self-efficacy were found to be significant in Emotional and Instrument support only on Self-confidence, In Emotional support and Feedback support only on Self-regulated efficacy & Emotional support and Instrument support only on Goal challenge were found to be a significant effect. Third, Self-regulated efficacy and Goal challenge in the Entrepreneurial self-efficacy on Entrepreneurial opportunity recognition were found to be a significant effect. All Self-confidence, Self-regulated efficacy & Goal challenge in the Entrepreneurial self-efficacy on Entrepreneurial opportunity assessment were found to be a significant effect. Fourth, Indirect effect of social support on entrepreneurial opportunity competence mediated by Entrepreneurial self-efficacy was found to be partially significant.

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Study the impact on job satisfaction in the care facility of the empowerment of the members of the organization (요양시설의 조직구성원의 임파워먼트가 직무만족에 미치는 영향에 관한 연구)

  • Kim, Chang-Tae;Gwak, Gyeong-Ja
    • Management & Information Systems Review
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    • v.31 no.4
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    • pp.57-82
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    • 2012
  • The purpose of the study is to suggest the measure for the improvement of job satisfaction and level of empowerment of sanatoriums' social workers by analyzing factors of empowerments' effect on the job satisfaction, and investigating level of empowerment and job satisfaction of social workers of sanatoriums for the elderly and the handicapped. The result of investigation and analysis on subjects of 420 social workers of sanatoriums for the elderly and the handicapped in Youngnam area for this is as follows: First, job characteristic that is empowerments' influence factor of sanatoriums' social workers is appeared in order of feedback, and function variety, and in organization characteristic is appeared in order of leadership, reward, and employee development. Second, level of empowerment that is recognized by sanatoriums' social workers is appeared a little higher than normal level and significance is appeared highest, and next are capability, self-determination ability, and influence. Third, features that showed significant difference with significance in general characteristic of sanatoriums' social workers were 'sex', 'marital status', and 'religion', and features that showed significant difference with capability were sex, age, marital status, academic background, and employment history. And features that showed significant difference with self-determination ability were sex, age, marital status, and employment history, and features that showed significant difference with influence were sex, age, employment history and types of facilities. Fourth, the whole average of job satisfaction of sanatoriums' social workers was 3.82 out of 5, which is generally high, features that showed significant difference statistically were age, marital status, academic background, employment history, and types of facilities. Thus, job satisfaction was appeared as high as 'more than age of thirty' in age, 'married' in marital status, 'under graduates of colleges' in academic background, and 'less than three years' in employment history. Fifth, as for factors that had influence on job satisfaction, the indirect effect with empowerment was appeared that had significant effect in organization characteristic, and had few effect in organization features. On these results, practical measures to increase job satisfaction of sanatoriums' social workers are as follows: First, political approach is required to standardize duty system(by various types of facilities and clients' characteristic) of social workers of sanatoriums for elderly and the handicapped, and help to do the role as professionals with giving better treatment and building self-respect by enough reward. Second, to suggest chances to perform the responsibility for the duty of the scenes by the regular supervision, establish regular supervision system of social workers of sanatoriums for the elderly and the handicapped, and the extension of duty to increase the functional varieties. Third, it is required to motivate to have self confidence for the work and to use potential ability with transforming leadership, and to have more chances of education for the self-development. To increase job satisfaction of sanatoriums' social workers who give direct services in sanatoriums for the elderly and the handicapped, more active and positive empowerment's level improvement is in need by improvement of empowerment for them.

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