• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.1
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• pp.341-353
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• 2014

In order to deliver a centimeter-level kinematic positioning solution with GPS carrier-phase measurements, it is prerequisite to use correctly resolved integer ambiguities. Based on the mathematical modeling of GPS network with application of its geometrical constraints, this research has investigated an instantaneous ambiguity resolution procedure for the so-called 'integer constrained least-squares' technique which can be effectively implemented in real-time structure monitoring. In this process, algorithms of quality control for the float solutions and hypothesis tests using the constrained baseline for the ambiguity validation are included to enhance reliability of the solutions. The proposed procedure has been implemented by MATLAB, the language of technical computing, and processed field trial data obtained at a cable-stayed bridge to access its real-world applicability. The results are summarized in terms of ambiguity successful rates, impact of the stochastical models, and computation time to demonstrate performance of the instantaneous ambiguity resolution proposed.

• Korean Journal of Occupational Health Nursing
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• v.27 no.2
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• pp.77-88
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• 2018

Purpose: This study aimed to investigate the degree of role conflict and its ambiguity, and fatigue in clinical nurses and to analyze the effect of these on their self-resilience in order to provide fundamental data for improving their working environment after the Middle East Respiratory Syndrome outbreak. Methods: After the collection of data from 258 clinical nurses in five general hospitals, t-test, ANOVA, Pearson's correlation coefficient, and multiple regression were performed using IBM SPSS Statistics 20.0. Results: A significant positive correlation was found between nurses' role conflict and ambiguity and fatigue; while a negative correlation was found between nurses' role conflict and ambiguity and self-resilience. A significant negative correlation was found between fatigue and self-resilience. According to the study results, the factor that affected clinical nurses' self-resilience the most was role conflict and its ambiguity, followed by marital status, fatigue, educational level, religion, and related tasks, which together accounted for 38% of self-resilience in clinical nurses. Conclusion: To improve weaknesses in nursing care after the Middle East Respiratory Syndrome outbreak, the scope of nursing care was changed upon the expansion of integrated nursing and care-giving services. Therefore, in the rapidly changing environment of nursing, policies to improve nursing performance, as well as successful reaction capability, are suggested.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.47 no.10
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• pp.1-7
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• 2010

A new frequency offset estimation algorithm for chirp spread spectrum based on matched filter is proposed. Generally, the differential phase between successive symbols is used for the conventional frequency offset estimation algorithm. However, if the conventional frequency offset estimation algorithm is used for CSS, phase ambiguity arises because of long symbol duration and guard time. The phase ambiguity causes performance degradation of matched filter since the received signal is corrupted by the integer frequency offset. In this paper, we propose a new frequency offset estimation algorithm which separates integer and fractional frequency offset estimation for removing the phase ambiguity. The proposed algorithm estimates the integer frequency offset by using differential phase between matched filtering results of sub-chirps and successive symbols. Then, the fractional frequency offset is estimated by using the differential phase between successive symbols Simulation results show that the proposed algorithm well removes the phase ambiguity, and have almost same estimation performance compared with conventional one when there is not the phase ambiguity.

• Korean Journal of Remote Sensing
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• v.28 no.2
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• pp.227-235
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• 2012

The InSAR (Interferometric SAR) processing steps for DEM generation consist of the coregistration of two SAR data, interferogram generation, phase filtering, phase unwrapping, phase to height conversion, and geocoding, etc. In this study, we developed the precise algorithm for phase to height conversion, including the ambiguity method taking into account Earth ellipsoid, Schw$\ddot{a}$visch method, and the refined ambiguity method suitable for the interferometric pair with non-parallel obit. From the testing with JERS-1 orbit we found that the height error by traditional ambiguity method reaches to about 40 m during phase to height conversion. The proposed methods are very useful in generating precise InSAR DEM;especially in the case of using non-parallel InSAR pair due to unstable orbit control such as JERS-1 or intentional orbit control such as Cross-InSAR pair between ERS2 and ENVISAT satellite.

• Journal of the Korea Society of Computer and Information
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• v.28 no.11
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• pp.169-180
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• 2023

The purpose of this study is to determine the relationship between role ambiguity, job burnout, and organizational effectiveness among nurses working in comprehensive nursing care service units and to investigate the mediating effect of job burnout on the relationship between role ambiguity and organizational effectiveness. The participants were 149 nurses working in 10 general hospitals. Data were collected using a self-report questionnaire and analyzed using IBM SPSS Statistics 25.0 and Model 4 of the PROCESS macro program. The results reveal that organizational effectiveness has a significant negative relationship with role ambiguity and job burnout, with job burnout completely mediating the effect of role ambiguity on organizational effectiveness. These findings suggest that interventions to reduce job burnout should be considered to enhance organizational effectiveness.

• The Journal of Information Systems
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• v.22 no.2
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• pp.51-83
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• 2013

Personal creativity is critically important for organizations seeking to survive and thrive in today's highly turbulent business environments. Organizations must effectively identify and mobilize the creative resources of their members. When organizational members perceive a work environment that restricts or fails to encourage individual creative expression, a gap may exist between the level of individual creative potential and the actual amount of individual creativity practiced within the organization. In this situation, this paper will examine the impact of role conflict, role ambiguity, creative self-efficacy, and personal initiative on personal creativity. Creative self-efficacy is the subjective belief in one's personal ability to be creative, that is, a personal assessment of one's own creative potential. A strong internal belief in one's ability to successfully engage in creative behaviors is generally considered an important part of the creative process. Personal Initiative refers to behaviors, mainly directed toward work and organizational issues, that are characterized by the following aspects: self-starting, proactive, and persistent in overcoming barriers. Creativity-related creative self-efficacy and personal initiative are critical components to understand motivation that coordinates the relationship between perception and behavior of individual employees. Based on role theory, researchers have focused on role conflict and role ambiguity as the two key ingredients of role stress. Role ambiguity is defined as an evaluation about the lack of salient information needed to perform a role effectively. Role conflict results from two or more sets of incompatible demands involving work-related issues. Employees are usually pursued work-roles more than one in work-focused organization. Too many work-roles and perceived uncertainties at employee's work can be obstacles to personal creativity. In an analysis of results, while role conflict is not negatively related significantly to creative self-efficacy, role ambiguity is negatively related significantly to creative self-efficacy. While role conflict is significantly related to personal creativity, role ambiguity is negatively related significantly to personal creativity. Creative self-efficacy mediates the relationship among role conflict, role ambiguity, and employee creativity. Personal initiative mediates the relationship between creative self-efficacy and employee creativity. This paper shows that creative self-efficacy and personal initiative are the driving force behind personal creativity. Organizations can get some implications of creative-related role conflict and role ambiguity that employees have experienced. As a result, organizations must not only encourage creativity of employees by greater involvement but also encourage their input towards their-focused own works and tasks. And employees should be developed to pace with the organizational needs and development. Management must enable employees to think of new ideas and practices that promotes personal creativity.

• Journal of Distribution Science
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• v.17 no.1
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• pp.105-115
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• 2019

Purpose - Previous research has shown that a very high level and a very low level of job scope can both be more stressful than intermediate levels of job scope. This study investigates the potential positive and negative effects of the number of accounts handled by sales personnel. The primary objective of this paper is to examine how the number of accounts salespeople handle affects their stress and performance. Research design, data, and methodology - This research conducted the data collection using a survey of salespeople in the pharmaceutical industry. I sent the survey to 420 salespeople, and received 318 usable responses. To assess measurement reliability and validity, I ran an exploratory and confirmatory factor analysis. I also employed structural equation modeling (SEM) to test all hypothesized effects in AMOS and also measured the interaction variable using Ping's (1996) approach. Results - These results show that there are linear and non-linear effects of the number of accounts handled by the salesperson on both role ambiguity and role conflict. First, the number of accounts handled by a salesperson is positively related to role ambiguity and role conflict. Second, the effect of the number of accounts handled on role ambiguity and role conflict decreases as the number of accounts handled by the salesperson increases. Third, as accounts increase from a low level, role stress increases; when the number of accounts reaches an optimal level, role stress decreases; and when the number of accounts increases to a high level, it can be detrimental to the salesperson's role stress. Fourth, while product complexity is positively related to role ambiguity, brand strength is negatively related to both role ambiguity and role conflict. Fifth, the greater the brand strength, the weaker the relationship will be between the number of accounts handled and salesperson role ambiguity. Finally, role ambiguity is positively related to salesperson performance. Conclusion - Too much and too little accounts increase the role ambiguity and role conflict of salespersons. Managers should identify the complex effect of the number of accounts handled by salespeople. Also, when products are complex, managers should provide training to eliminate any complex processes and complex information. These results suggest ways to decrease salespersons' role stress by ensuring an optimal level of the number of accounts and brand strength.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.4
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• pp.958-963
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• 2008

Korean language has different structural properties which are controlled by semantic constraints of verbs. Also, most of Korean sentences are complex sentences which consisted of main clause and embedded clause. Therefore it is difficult to describe appropriate syntactic grammar or constraint for the Korean language and the Korean parsing causes various syntactic ambiguities. In this paper, we suggest how to describe CFG-based grammar using sentence patterns as syntactic constraint and solve syntactic ambiguities. To solve this, we classified 44 sentence patterns including complex sentences which have subordinate clause in Korean sentences and used it to reduce syntactic ambiguity. However, it is difficult to solve every syntactic ambiguity using the information of sentence patterns. So, we used semantic markers with semantic constraint. Semantic markers can be used to solve ambiguity by auxiliary particle or comitative case particle.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1211-1215
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• 2005

In the GPS attitude determination system, the baseline length constraints can be used efficiently to reduce the search space. It is possible by adopting the assumptions that the baseline length doesn't change and the true baseline length is precisely known. But in real situation, the baseline length might be changed by many reasons and it is impossible to measure the true baseline length because there exists measurement error and antenna phase centre movement. In order to analyze the effect of the baseline length accuracy, one needs to know the relation between the accuracy of the baseline length and success rates of the integer ambiguity resolution. In this paper, the effect of the baseline length accuracy to the integer ambiguity resolution in the attitude determination system is analyzed by empirical method. The results show that the margins in the baseline length accuracy is less than a few cm which implies that one should take great cares when applying the attitude determination system to the flexible structures.

• Journal of Agricultural Extension & Community Development
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• v.12 no.1
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• pp.69-81
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• 2005

The objectives of this study were to measure role conflict of 4-H leaders and to verify the differences of role conflict and self-efficacy according to individual characteristics. The data were collected from 99 leaders who took charge of guiding 4-H youth organization in school as teacher advisor. The statistical techniques used for this study were frequency, t-test, one-way analysis of variance and correlation. The major findings of this study were as follows; 1) The 4-H leaders had some role conflict and role ambiguity in guiding youth activities in the school. 2) The leader advisor group with teaching experience of $5{\sim}9$ years showed higher role conflict and lower role ambiguity. 3) The 4-H leaders with age over 45 felt higher role conflict and lower role ambiguity. 4)The leaders' self-efficacy was positively correlated with self esteem, and negatively associated with role ambiguity.